libclc: Add a __builtin to let SPIRV targets select between SW and HW FMAReviewer: jenatali jveselyDifferential Revision: https://reviews.llvm.org/D85910
libclc/spirv: Add missing files from D85911Fixes: 060c8e083dd637866854acb6a0823c45b2ef68efSigned-off-by: Jan Vesely <[email protected]>