Adding argument attributes 'mut' and 'ref'

[SuperFola]

Description

This allows setting function arguments as mut or ref (read-only). All function arguments are now, by default, immutable.

I still need to add way more tests for the ref attribute, to ensure nothing is breaking, and document everything. It basically avoids a reference unboxing when storing arguments inside functions.

Closes #612

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	493:2030	Ark::VM::safeRun	3	1284	259
src/arkreactor/Compiler/Macros/Processor.cpp	253:637	Ark::internal::MacroProcessor::evaluate	3	354	122
src/arkreactor/Compiler/BytecodeReader.cpp	297:710	Ark::BytecodeReader::display	4	364	112
src/arkreactor/Compiler/Lowerer/ASTLowerer.cpp	568:743	Ark::internal::ASTLowerer::handleCalls	4	133	43
src/arkscript/JsonCompiler.cpp	27:276	JsonCompiler::_compile	1	214	38
src/arkreactor/Compiler/NameResolution/NameResolutionPass.cpp	161:266	Ark::internal::NameResolutionPass::visitKeyword	3	85	35
src/arkreactor/Compiler/AST/Parser.cpp	837:928	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/Lowerer/ASTLowerer.cpp	138:241	Ark::internal::ASTLowerer::compileExpression	4	85	27
src/arkreactor/Compiler/Macros/Processor.cpp	102:185	Ark::internal::MacroProcessor::processNode	3	61	27
src/arkreactor/Compiler/AST/Node.cpp	287:368	Ark::internal::Node::debugPrint	1	70	26
src/arkreactor/Compiler/NameResolution/NameResolutionPass.cpp	55:159	Ark::internal::NameResolutionPass::visit	2	83	23
src/arkreactor/Compiler/AST/Parser.cpp	288:416	Ark::internal::Parser::import_	1	98	23
src/arkreactor/Compiler/Lowerer/ASTLowerer.cpp	270:329	Ark::internal::ASTLowerer::compileListInstruction	3	49	22
src/arkreactor/VM/VM.cpp	2150:2254	Ark::VM::backtrace	3	89	22
src/arkscript/Formatter.cpp	173:235	Formatter::format	3	59	18
src/arkscript/Formatter.cpp	488:534	Formatter::formatCall	2	42	18
src/arkreactor/Compiler/Macros/Processor.cpp	719:760	Ark::internal::MacroProcessor::isConstEval	1	37	18
src/arkreactor/Compiler/Lowerer/ASTLowerer.cpp	370:449	Ark::internal::ASTLowerer::compileFunction	3	57	16
src/arkscript/Formatter.cpp	285:326	Formatter::formatFunction	2	35	15
src/arkreactor/Compiler/Lowerer/ASTLowerer.cpp	78:94	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/Error/Diagnostics.cpp	43:187	Ark::Diagnostics::makeContext	4	105	43
src/arkscript/main.cpp	23:323	main	2	255	29
src/arkreactor/TypeChecker.cpp	110:194	Ark::types::generateError	5	72	24
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/arkscript/REPL/Utils.cpp	52:184	Ark::internal::getColorPerKeyword	0	110	19
src/arkreactor/Compiler/NameResolution/StaticScope.cpp	68:109	Ark::internal::NamespaceScope::get	3	32	19
src/arkreactor/VM/Value.cpp	77:140	Ark::Value::toString	1	50	19
src/arkreactor/TypeChecker.cpp	28:108	Ark::types::displayContract	4	70	19
src/arkreactor/Compiler/Macros/Executors/Function.cpp	16:91	Ark::internal::FunctionExecutor::applyMacro	2	55	17
include/Ark/Compiler/AST/Predicates.hpp	132:156	Ark::internal::IsSymbol::operator ( )	1	24	16
src/arkreactor/Compiler/Macros/Executors/Function.cpp	101:158	Ark::internal::FunctionExecutor::unify	5	50	15
src/arkreactor/Compiler/IntermediateRepresentation/IROptimizer.cpp	12:206	Ark::internal::IROptimizer::IROptimizer	1	170	4
src/arkreactor/Error/Diagnostics.cpp	189:202	Ark::Diagnostics::helper	6	13	2

---

CppCheck report

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/IO.cpp	165	style	Consider using std::transform algorithm instead of a raw loop.
src/arkreactor/Compiler/BytecodeReader.cpp	476	style	struct member 'Arg::kind' is never used.
src/arkreactor/VM/VM.cpp	494	information	Limiting ValueFlow analysis in function 'safeRun' since it is too complex. Please specify --check-level=exhaustive to perform full analysis.
src/arkreactor/VM/VM.cpp	713	style	Variable 'tmp' can be declared as pointer to const
src/arkreactor/VM/VM.cpp	372	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
src/arkreactor/Builtins/Bytecode.cpp	22	style	Parameter 'vm' can be declared as pointer to const
src/arkreactor/Compiler/NameResolution/ScopeResolver.cpp	134	style	Consider using std::find_if algorithm instead of a raw loop.
include/Ark/VM/Future.hpp	50	style	Unused private function: 'Future::deleteSelfViaVM'
src/arkreactor/VM/Future.cpp	23	performance	Variable 'm_value' is assigned in constructor body. Consider performing initialization in initialization list.
src/arkreactor/VM/State.cpp	190	style	Consider using std::any_of, std::all_of, std::none_of algorithm instead of a raw loop.

[coveralls]

coverage: 90.564% (+0.008%) from 90.556%
when pulling 673cbc5 on feat/ref
into 0bb7859 on dev.

[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 : 40 thousands
 Cumulative speed : 135 execs/sec
    Pending items : 152 faves, 1230 total
 Coverage reached : 11.89%
    Crashes saved : 0
      Hangs saved : 0

Cycles without finds : 0
Time without finds : 0

[+] Captured 41941 tuples (map size 221738, highest value 255, total values 398486968) in '/dev/null'.
[+] A coverage of 41941 edges were achieved out of 221760 existing (18.91%) with 1239 input files.

[codspeed-hq]

CodSpeed Performance Report

Merging #613 will degrade performances by 1.34%

_{Comparing feat/ref (673cbc5) with dev (0bb7859)}

Summary

❌ 1 (👁 1) regression
✅ 16 untouched
🆕 1 new

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
🆕	create_list_with_ref	N/A	6 ms	N/A
👁	Welder - Big - 665 nodes[2]	39.4 ms	39.9 ms	-1.34%