Change #if DAWN_PLATFORM_XXX to #if DAWN_PLATFORM_IS(XXX)
To prevent #ifdef usage and reference without including
dawn/common/Platform.h
Also change #if DAWN_COMPILER_XXX to # if DAWN_COMPILER_IS(XXX)
Bug: dawn:1447
Change-Id: If6c9dab15fd2676f9a087507f5efcceeff468d33
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/92625
Commit-Queue: Shrek Shao <shrekshao@google.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>