Add support for building and testing Folly on Windows ARM64

[Harishmcw]

The PR adds support for building and testing Folly on Windows ARM64 using MSVC Compiler.

Changes Proposed:

• Created Workflow file for building and testing Folly on Windows ARM64 [getdeps_windows_arm64.yml].
• Enabled Windows ARM64 build configurations in builder, platform, and build options scripts.
• Modified builder script to exclude problematic build options for building Boost library on Windows ARM64.
• Modified Portability header[Portability.h] to enable NEON SIMD and exclude problematic coroutine test builds for Windows ARM64.
• Replaced unsupported NEON vector operator usage with explicit intrinsic to ensure MSVC ARM64 compatibility (find_first_of.h).
• Replaced unsupported builtin functions with MSVC ARM64 intrinsics for popcount, ctz, and clz (Instructions.h, Bits.h).
• Implemented 128-bit multiplication using __umulh on MSVC ARM64, where _mul128 and __int128 are unavailable (F14Table.h).
• Added a Windows ARM64 fallback for FiberImpl using the Windows Fibers API due to lack of boost::context support (BoostContextCompatibility.h)
• Added MSVC ARM64 support for pause using __yield() as the equivalent of _mm_pause() (Asm.h).