[Clang] Enable __has_feature(coverage_sanitizer)

Like other sanitizers, enable __has_feature(coverage_sanitizer) if clang
has enabled at least one SanitizerCoverage instrumentation type.

Because coverage instrumentation selection is not handled via normal
-fsanitize= (and thus not in SanitizeSet), passing this information
through to LangOptions required propagating the already parsed
-fsanitize-coverage= options from CodeGenOptions through to LangOptions
in FixupInvocation().

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D103159