Fix/tail calls binding

[SuperFola]

Description

Tail calls avoid the usual mechanism for calling functions and directly jump to the top of the function, after having pushed the arguments for the call. Then the function does its usual STORE <arg>.... However, in the following code sample

(let f (fun (a b) {
  (let x a)
  (if (= 1 a)
    (f "correct" "wrong")
    x) }))
(print (f 1 2))

x would be bound to a using a STORE_FROM_INDEX, which works on the first call but not after performing the tail call, as the locals stack isn't reset, and STORE_FROM_INDEX is called with index 1 which points to b instead of a, since the stack now holds (a, b, x).

This PR adds a new instruction TAIL_CALL_SELF which handles the jump to 0 and resets the scope (only resets indices, does not erase values from the stack, as this is useless).

Checklist

• I have read the Contributor guide
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation if needed (on https://github.com/ArkScript-lang/website, content/docs/)
• I have added tests that prove my fix/feature is working
• New and existing tests pass locally with my changes

[github-actions]

Static analysis report

Lizard report

Listing only functions with cyclomatic complexity >= 15 or NLOC >= 100 or parameters >= 6.

Filename	Start line:end line	Function name	Parameters	NLOC	CCN
src/arkreactor/VM/VM.cpp	408:2094	Ark::VM::safeRun	3	1413	277
src/arkreactor/Compiler/Lowerer/ASTLowerer.cpp	195:299	Ark::internal::ASTLowerer::compileExpression	4	87	29
src/arkreactor/Compiler/Lowerer/ASTLowerer.cpp	333:392	Ark::internal::ASTLowerer::compileListInstruction	3	49	22
src/arkreactor/VM/VM.cpp	2247:2341	Ark::VM::backtrace	3	81	19
src/arkreactor/Compiler/Lowerer/ASTLowerer.cpp	732:784	Ark::internal::ASTLowerer::handleOperator	3	42	18
src/arkreactor/Compiler/Lowerer/ASTLowerer.cpp	459:537	Ark::internal::ASTLowerer::compileFunction	3	56	16
src/arkreactor/Compiler/Lowerer/ASTLowerer.cpp	96:112	Ark::internal::ASTLowerer::nodeProducesOutput	1	13	15

Report about files you didn't modify in this PR

Filename	Start line:end line	Function name	Parameters	NLOC	CCN
src/arkreactor/Compiler/Macros/Processor.cpp	259:628	Ark::internal::MacroProcessor::evaluate	3	338	114
src/arkreactor/Compiler/BytecodeReader.cpp	297:717	Ark::BytecodeReader::display	4	371	113
src/arkreactor/Error/Diagnostics.cpp	45:192	Ark::Diagnostics::makeContext	4	109	44
src/arkscript/main.cpp	23:382	main	2	310	43
src/arkscript/JsonCompiler.cpp	27:276	JsonCompiler::_compile	1	214	38
src/arkreactor/Compiler/NameResolution/NameResolutionPass.cpp	162:267	Ark::internal::NameResolutionPass::visitKeyword	3	85	35
src/arkreactor/Builtins/Slice.cpp	21:93	Ark::internal::Builtins::slice	1	63	34
src/arkreactor/Compiler/AST/Parser.cpp	841:932	Ark::internal::Parser::string	1	88	32
src/arkreactor/Compiler/AST/Node.cpp	179:285	Ark::internal::Node::repr	0	90	30
src/arkreactor/Compiler/Macros/Processor.cpp	107:191	Ark::internal::MacroProcessor::processNode	3	63	28
src/arkreactor/Compiler/AST/Node.cpp	287:368	Ark::internal::Node::debugPrint	1	70	26
src/arkreactor/TypeChecker.cpp	149:236	Ark::types::generateError	6	75	25
src/arkreactor/TypeChecker.cpp	32:147	Ark::types::displayContract	6	102	24
src/arkreactor/Compiler/NameResolution/NameResolutionPass.cpp	56:160	Ark::internal::NameResolutionPass::visit	2	83	23
src/arkreactor/Compiler/AST/Parser.cpp	289:417	Ark::internal::Parser::import_	1	98	23
include/utf8.hpp	138:184	utf8::isValid	1	44	21
src/arkreactor/Compiler/AST/Optimizer.cpp	33:83	Ark::internal::Optimizer::countAndPruneDeadCode	1	42	20
src/arkreactor/VM/Value/Value.cpp	77:142	Ark::Value::toString	2	52	20
src/arkreactor/Compiler/NameResolution/StaticScope.cpp	68:109	Ark::internal::NamespaceScope::get	3	32	19
src/arkscript/Formatter.cpp	503:562	Formatter::formatCall	2	51	19
src/arkscript/Formatter.cpp	188:250	Formatter::format	3	59	18
src/arkreactor/Compiler/IntermediateRepresentation/IROptimizer.cpp	22:265	Ark::internal::IROptimizer::IROptimizer	1	224	17
src/arkreactor/Compiler/Macros/Executors/Function.cpp	16:89	Ark::internal::FunctionExecutor::applyMacro	2	56	17
include/Ark/Compiler/AST/Predicates.hpp	132:156	Ark::internal::IsSymbol::operator ( )	1	24	16
src/arkscript/Formatter.cpp	300:341	Formatter::formatFunction	2	35	16
src/arkreactor/Compiler/Macros/Executors/Function.cpp	99:156	Ark::internal::FunctionExecutor::unify	5	50	15
src/arkreactor/VM/Debugger.cpp	146:206	Ark::internal::Debugger::prompt	2	54	15
src/arkreactor/Error/Diagnostics.cpp	194:211	Ark::Diagnostics::helper	7	17	2

---

CppCheck report

Filename	Line	Type	Description
src/arkreactor/VM/VM.cpp	282	error	Iterators of different containers 'm_execution_contexts.emplace_back(std::make_unique())' and 'm_execution_contexts.front()' are used together.

Report files about files you didn't modify in this PR

Filename	Line	Type	Description
include/Ark/VM/VM.inl	255	style	Variable 'maybe_value_ptr' can be declared as pointer to const
src/arkreactor/Builtins/Bytecode.cpp	23	style	Parameter 'vm' can be declared as pointer to const
src/arkreactor/Builtins/IO.cpp	165	style	Consider using std::transform algorithm instead of a raw loop.
src/arkreactor/Compiler/BytecodeReader.cpp	477	style	struct member 'Arg::kind' is never used.
src/arkreactor/Compiler/IntermediateRepresentation/IROptimizer.cpp	254	style	Consider using std::transform algorithm instead of a raw loop.
src/arkreactor/Compiler/IntermediateRepresentation/IROptimizer.cpp	261	style	Consider using std::transform algorithm instead of a raw loop.
src/arkreactor/Compiler/NameResolution/ScopeResolver.cpp	134	style	Consider using std::find_if algorithm instead of a raw loop.
include/Ark/VM/Value/Future.hpp	50	style	Unused private function: 'Future::deleteSelfViaVM'
src/arkreactor/VM/Value/Future.cpp	23	performance	Variable 'm_value' is assigned in constructor body. Consider performing initialization in initialization list.

[codspeed-hq]

Merging this PR will degrade performance by 7%

❌ 1 (👁 1) regressed benchmark
✅ 17 untouched benchmarks

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
👁	ackermann	320.6 ms	344.8 ms	-7%

---

_{Comparing fix/tail-calls-binding (f5896c6) with dev (3654654)}

[github-actions]

Fuzzing report

/usr/local/bin/afl-whatsup status check tool for afl-fuzz by Michal Zalewski

Summary stats

    Fuzzers alive : 0
   Dead or remote : 1 (included in stats)
   Total run time : 5 minutes, 0 seconds
      Total execs : 37 thousands
 Cumulative speed : 126 execs/sec
    Pending items : 136 faves, 1221 total
 Coverage reached : 10.74%
    Crashes saved : 0
      Hangs saved : 0

Cycles without finds : 0
Time without finds : 0

[+] Captured 42876 tuples (map size 238646, highest value 255, total values 443393049) in '/dev/null'.
[+] A coverage of 42876 edges were achieved out of 238656 existing (17.97%) with 1229 input files.