In the cross-DSO CFI mode clang emits cfi_check_fail that handles
errors triggered from other modules with targets in the current
module. With this change, cfi_check_fail will handle errors for
CFI kinds that are not enabled in the current module as if they
have the trapping behaviour (-fsanitize-trap=...).
This fixes a bug where some combinations of -fsanitize* flags may
result in a link failure due to a missing sanitizer runtime library
for the diagnostic calls in __cfi_check_fail.