This patch add DXC compile flag "-enable-16bit-types" and change profile
to SM6.2 when validating generated HLSL using DXC if f16 extension is
enabled in the WGSL program.
The patch add Tint end-to-end test cases for expressions using f16 type,
including constructor, binary operator, splat, zero-init, and others.
Testcases that use f16 types in uniform or storage buffer are SKIPped,
because such usage is not implemented yet.
Bug: tint:1473, tint:1502
Change-Id: I481ab3d12cbb822f11ef85ba807bca3f9770089b
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/96252
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@chromium.org>
Commit-Queue: Zhaoming Jiang <zhaoming.jiang@intel.com>
