Use -verify -fsyntax-only and expected-no-diagnostics as
recommended by Paul.
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D77393
Warnings in emmintrin.h and xmmintrin.h are reported by
-fsanitize=implicit-integer-sign-change.
Reviewed By: RKSimon, craig.topper
Differential Revision: https://reviews.llvm.org/D77393