Can't take the address of an extern variable as a constant value

[yvt]

extern var external_variable: u32;
export const p_external_variable = &external_variable; // Error

var internal_variable: u32 = 42;
export const p_internal_variable = &internal_variable; // OK

Expected: Successful compilation

Actual:

<source>:2:36: error: cannot store runtime value in compile time variable
export const p_external_variable = &external_variable;
                                   ^

Compiler Explorer Link

[iacore]

This doesn't make sense at compile time if the symbol is not already defined (for example, when the symbol has weak linkage).

See #6789 (comment)