This patch implement modf and frexp built-ins for f16 types, and also
simplify their implementation for f32 in MSL and HLSL, and clean up
deprecated code in GLSL writer. Corresponding unittests are also
implemented, but end-to-end tests for f16 are not implemented yet.
Bug: tint:1473, tint:1502
Change-Id: I12887ae5303c6dc032a51f619e1afeb19b4603b6
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/98102
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Zhaoming Jiang <zhaoming.jiang@intel.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
20cddbf04c