Add support for float/int bitcast intrinsics in SPIR-V.

Change-Id: I1d5a056e08ba6e67016e45c52518da6074a62c8f
Bug: skia:11071
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/342759
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
5 files changed