Add bitwise not operator support with tests

[dheeraxspidey]

Summary

Adds support for bitwise NOT operator (~) and comprehensive bitwise operation testing across the shader translation pipeline.

Related Issue

No specific issue - adding core functionality for bitwise operations support.

Changes

• Added bitwise NOT operator support in lexer and parser
• Added comprehensive tests for bitwise operations:
  • Basic bitwise NOT operations
  • Combined bitwise expressions (AND, OR, XOR)
  • Test coverage for both lexer and parser
• Updated parsers across different backends to handle bitwise NOT:
  • DirectX backend
  • Metal backend
  • Added proper token recognition
  • Added AST node generation for bitwise operations

Testing

• Added new test cases:
  • test_bitwise_not() - Tests basic bitwise NOT operation
  • test_bitwise_expressions() - Tests combined bitwise operations
  • Added lexer tests to verify proper tokenization
  • Added parser tests to verify proper AST generation
• All existing tests pass (189 passed, 81 warnings)
• Manually tested with sample shader code

Shader Sample

crossgl
shader test {
void main() {
int a = 5;
int b = ~a; // Bitwise NOT
int c = a & b; // Combined with other bitwise ops
}
}

Checklist

• Tests cover new or changed code
• Everything builds and runs locally
• Only touched files related to the feature
• Added comprehensive test coverage