feat: advanced L-value parsing and robust LLVM codegen for structs, arrays, and inline asm

[LunaStev]

This PR significantly enhances Wave's capability to handle complex data structures and low-level operations. By implementing recursive L-value parsing and a more robust LLVM backend, the compiler now supports chained memory access (e.g., obj.field[index].subfield), proper array literal initialization, and sophisticated type coercion for inline assembly and function calls.

Key Changes

1. Advanced Parser & L-value Logic

• Chained Accessors: Implemented parse_lvalue_tail to support recursive field access (.) and indexing ([]). This allows expressions like a.b[i].c to be treated as a single assignable target.
• Robust Struct Parsing: Refactored parse_struct to better handle whitespace, newlines, and improved field type detection.
• Generic Type Parsing: Updated parse_type_from_stream to use a centralized collector for generic types, ensuring consistent handling of types like ptr<T> or ptr<ptr<i32>>.
• Assignability Validation: Integrated is_assignable checks during assignment parsing to prevent invalid operations on non-L-value expressions.

2. LLVM Backend & Codegen Overhaul

• Recursive Address Resolution: Heavily refactored generate_address_ir in address.rs. It now recursively navigates through structs and arrays to calculate precise memory addresses for nested data structures.
• Array Literals: Added gen_array_literal to generate IR for array initializers and improved IndexAccess to handle both pointer-based and value-based indexing seamlessly.
• Inline Assembly (ASM) Upgrades: Overhauled gen_asm_stmt_ir to support various output types. It now performs automatic bitcasting and coercion between integers, pointers, and floats to match assembly register requirements.
• Null Pointer Support: Added the null keyword as a native constant for null pointers across the backend.
• Argument Coercion: Improved function call logic to automatically handle pointers-to-arrays and pointers-to-structs, simplifying passing complex data to functions.

3. Tooling

• Test Runner: Updated run_tests.py with specific configurations for new test cases and dependency tracking.