x86: Code Generation Helpers

[BradleyWood]

Many patterns emerge when performing code generation work, such as loops, loading constants, broadcasting values, etc. This PR aims to address these common patterns by introducing reusable helpers, making the codebase cleaner, more maintainable, and easier to extend.

Helpers

• Creation of Loop Generation Helpers – New helper functions streamline the generation of loops in code generation.
• Relocation of Load Constant Helpers – Functions for loading constants have been moved into CodegenUtils to improve organization and reusability.
• Introduction of Register Management Macros – Helper macros improve register handling, making code clearer and more maintainable.
• Addition of SIMD Opcode Vector Length Helper – A new function determines the vector length for given SIMD opcodes, optimizing SIMD instruction generation.
• Migration of Broadcast Logic to CodegenUtils – The logic for broadcasting values has been centralized within CodegenUtils, improving modularity.

[BradleyWood]

@0xdaryl @hzongaro @a7ehuo @jdmpapin Can I get some high level opinions on the direction of this work? I don't need a full review at this time, but I want some opinions on this and what else, if anything, can be done to simplify various patterns in code-generation work.