Allow global variable initialisation only using the compile_item value

[Thirumalai-Shaktivel]

Fixes: #1667

[czgdp1807]

Using your PR, please show the indented ASR for this code.

[Thirumalai-Shaktivel]

(TranslationUnit
    (SymbolTable
        1
        {
            _global_symbols:
                (Module
                    (SymbolTable
                        5
                        {
                            _lpython_main_program:
                                (Function
                                    (SymbolTable
                                        4
                                        {
                                            
                                        })
                                    _lpython_main_program
                                    (FunctionType
                                        []
                                        ()
                                        Source
                                        Implementation
                                        ()
                                        .false.
                                        .false.
                                        .false.
                                        .false.
                                        .false.
                                        []
                                        []
                                        .false.
                                    )
                                    [test]
                                    []
                                    [(=
                                        (Var 5 x)
                                        (FunctionCall
                                            5 test
                                            ()
                                            []
                                            (Integer 4 [])
                                            ()
                                            ()
                                        )
                                        ()
                                    )
                                    (=
                                        (Var 5 j)
                                        (Var 5 i)
                                        ()
                                    )]
                                    ()
                                    Public
                                    .false.
                                    .false.
                                ),
                            i:
                                (Variable
                                    5
                                    i
                                    []
                                    Local
                                    (IntegerConstant 10 (Integer 4 []))
                                    (IntegerConstant 10 (Integer 4 []))
                                    Default
                                    (Integer 4 [])
                                    Source
                                    Public
                                    Required
                                    .false.
                                ),
                            j:
                                (Variable
                                    5
                                    j
                                    []
                                    Local
                                    ()
                                    ()
                                    Default
                                    (Integer 4 [])
                                    Source
                                    Public
                                    Required
                                    .false.
                                ),
                            test:
                                (Function
                                    (SymbolTable
                                        2
                                        {
                                            _lpython_return_variable:
                                                (Variable
                                                    2
                                                    _lpython_return_variable
                                                    []
                                                    ReturnVar
                                                    ()
                                                    ()
                                                    Default
                                                    (Integer 4 [])
                                                    Source
                                                    Public
                                                    Required
                                                    .false.
                                                ),
                                            temp:
                                                (Variable
                                                    2
                                                    temp
                                                    []
                                                    Local
                                                    ()
                                                    ()
                                                    Default
                                                    (Integer 4 [])
                                                    Source
                                                    Public
                                                    Required
                                                    .false.
                                                )
                                        })
                                    test
                                    (FunctionType
                                        []
                                        (Integer 4 [])
                                        Source
                                        Implementation
                                        ()
                                        .false.
                                        .false.
                                        .false.
                                        .false.
                                        .false.
                                        []
                                        []
                                        .false.
                                    )
                                    []
                                    []
                                    [(=
                                        (Var 2 temp)
                                        (IntegerConstant 0 (Integer 4 []))
                                        ()
                                    )
                                    (=
                                        (Var 2 _lpython_return_variable)
                                        (Var 2 temp)
                                        ()
                                    )
                                    (Return)]
                                    (Var 2 _lpython_return_variable)
                                    Public
                                    .false.
                                    .false.
                                ),
                            x:
                                (Variable
                                    5
                                    x
                                    []
                                    Local
                                    ()
                                    ()
                                    Default
                                    (Integer 4 [])
                                    Source
                                    Public
                                    Required
                                    .false.
                                )
                        })
                    _global_symbols
                    []
                    .false.
                    .false.
                ),
            main_program:
                (Program
                    (SymbolTable
                        3
                        {
                            _lpython_main_program:
                                (ExternalSymbol
                                    3
                                    _lpython_main_program
                                    5 _lpython_main_program
                                    _global_symbols
                                    []
                                    _lpython_main_program
                                    Public
                                )
                        })
                    main_program
                    [_global_symbols]
                    [(SubroutineCall
                        3 _lpython_main_program
                        ()
                        []
                        ()
                    )]
                )
        })
    []
)

[czgdp1807]

Makes sense to me.

[Thirumalai-Shaktivel]

Thanks of the approvals!