* sancov.c: New file.
	* Makefile.in (OBJS): Add sancov.o.
	* invoke.texi (-fsanitize-coverage=trace-pc): Describe.
	* passes.def (sancov_pass): Add.
	* tree-pass.h  (sancov_pass): Add.
	* common.opt (-fsanitize-coverage=trace-pc): Add.
	* sanitizer.def (BUILT_IN_SANITIZER_COV_TRACE_PC): Add.
	* builtins.def (DEF_SANITIZER_BUILTIN): Enable for
	flag_sanitize_coverage.

From-SVN: r231296