feat: improve inline asm parsing and type safety

[LunaStev]

This PR enhances the inline assembly (asm) block functionality and strengthens the compiler's type system. By supporting generic expressions as assembly operands and implementing a robust type coercion layer, Wave now allows for more expressive low-level programming (such as syscall wrappers) while maintaining higher safety standards during code generation.

Key Changes

1. Advanced Inline ASM Parsing

• Expression Support: asm blocks now accept generic Expression variants for in and out clauses. This allows for literals (decimal, hex, binary), variable references, address-of (&x), and dereferences (deref x).
• Operand Management:
  • Introduced parse_asm_operand and parse_asm_inout_clause for cleaner, more maintainable parsing logic.
  • Implemented is_assignable checks to ensure that out operands are valid L-values (memory locations that can be written to).

2. LLVM Codegen & Type Coercion

• Multi-Output Support: Refactored gen_asm_stmt_ir to support multiple assembly outputs by utilizing LLVM struct return types.
• Operand Translation: asm_operand_to_value now converts AST expressions to LLVM values while preserving radix information (hex/binary) for literals.
• Coercion Engine:
  • Implemented coerce_basic_value and coerce_to_expected to handle implicit widening (e.g., i32 to i64) and explicit pointer casting.
  • This is particularly useful for syscalls where integers must often be treated as pointers and vice versa.
• Output Storage: store_asm_output correctly writes assembly results back to Wave variables, handling necessary pointer-bitcasts.

3. Type System & Error Reporting

• Radix Preservation: The lexer now produces an IntLiteral token that stores the raw string representation. This allows the backend to correctly interpret different numeric bases.
• UI/UX: Integrated the colorex crate into front/error to provide helpful, color-coded error messages in the terminal.
• Initialization Safety: gen_variable_ir now utilizes the coercion engine to ensure initializers are safely promoted to the variable's declared type.

4. Testing & Infrastructure

• Syscall Verification: Updated test56.wave to demonstrate new assembly features via type-safe syscall wrappers (syscall4i, syscall4p).
• Stability:
  • Fixed array sizing in test66.wave.
  • Added explicit type annotations to overflow tests in test69.wave.
  • Updated the test runner to mark test56.wave as a known timeout (due to its server-like nature).

Benefits

• Versatility: Inline assembly is now powerful enough to write sophisticated system-level abstractions.
• Safety: Stricter type checking and L-value validation catch errors before they reach the LLVM optimizer.
• Clarity: Radix preservation and colored errors improve the developer experience.