Add support to trace comparison instructions and switch statements

[Jakub Jelinek]

On Wed, Sep 06, 2017 at 04:37:18PM +0200, Jakub Jelinek wrote:
> Ok.  Please make sure those entrypoints make it into the various example
> __sanitier_cov_trace* fuzzer implementations though, so that people using
> -fsanitize-coverage=trace-cmp in GCC will not need to hack stuff themselves.
> At least it should be added to sanitizer_common (both in LLVM and GCC).

Forgot to say that I've committed the patch to GCC trunk today.

	Jakub