Feat: Implement Bitwise Operations and Unary Operators

[LunaStev]

Summary

This PR adds support for bitwise operations (Shift, XOR, NOT) and unary operators (Logical NOT, Bitwise NOT). It also refactors the expression parsing logic to ensure proper operator precedence, completing a robust set of industry-standard operators for Wave.

Key Changes

1. Lexer & Syntax Update

• C-style Shift Operators: Changed the shift keywords from rol/ror to standard << (Shift Left) and >> (Shift Right) syntax.
• Internal Mapping: Maintained TokenType::Rol and TokenType::Ror internally for consistency.

2. AST Enhancements

• Added new operator variants to Expression and Operator enums:
  • Binary: <<, >>, ^
  • Unary: ! (Logical NOT), ~ (Bitwise NOT)
• Introduced Expression::Unary to represent prefix operations.

3. Parser Refactoring (Precedence Hierarchy)

• Refined the expression parsing tree to handle complex operations with correct precedence:
  • Hierarchy: Logical > Bitwise (|, ^) > Shift (<<, >>) > Relational (<, >, etc.).
• Added parse_bitwise_expression and parse_shift_expression methods.

4. LLVM Code Generation

• Implemented IR generation for new operations:
  • build_left_shift and build_right_shift for bitwise shifts.
  • build_not for bitwise NOT (~).
  • build_xor with const_int(1) for logical NOT (!).

5. Comprehensive Testing (test70.wave)

• Added a full-scale operator test suite covering:
  • Arithmetic and Compound assignment.
  • Comparison and Logical operations.
  • Bitwise manipulation and Shift results.
  • Complex grouping and precedence validation.

Example Usage

var x: i32 = 10;
var y: i32 = x << 2;     // result: 40
var z: i32 = ~x;         // result: -11
var w: bool = !(x > 5);  // result: false