[SPIR-V] Complete SPV_INTEL_16bit_atomics extension support (#184312)
Add missing capabilities to finalize SPV_INTEL_16bit_atomics extension:
- AtomicInt16CompareExchangeINTEL (6260): for i16
load/store/exchange/cmpxchg
- Int16AtomicsINTEL (6261): for i16 arithmetic atomics (add, sub, min,
max, etc.)
- AtomicBFloat16LoadStoreINTEL (6262): for bfloat16 load/store/exchange
This completes the implementation started in 6ef3218.
Specification:
https://github.com/intel/llvm/blob/sycl/sycl/doc/design/spirv-extensions/SPV_INTEL_16bit_atomics.asciidoc