Unify x64 and arm64 build process in build_llvm_release.bat (#131687)
This patch unifies x64 and arm64 build process in Windows release script
by consolidating common functionality while preserving architecture
specific requirements.
Key changes include:
- Combined x64 and arm64 build logic into do_build_64_common
- Added PGO support for arm64 builds
- Added flang and mlir projects to x64 builds
- Remove LLDB from stage 0 builds and consolidate common LLDB flags
- Build sanitizers for x64 while disable them on arm64.
- Use LLVM_ENABLE_RUNTIMES for including runtime projects