match.pd: Defer some CTZ/CLZ foldings until after ubsan pass for -fsanitize=builtin...

match.pd: Defer some CTZ/CLZ foldings until after ubsan pass for -fsanitize=builtin [PR115127]

As the following testcase shows, -fsanitize=builtin instruments the
builtins in the ubsan pass which is done shortly after going into
SSA, but if optimizations optimize the builtins away before that,
nothing is instrumented.  Now, I think it is just fine if the
result of the builtins isn't used in any way and we just DCE them,
but in the following optimizations the result is used.
So, the following patch for -fsanitize=builtin only defers the
optimizations that might turn single argument CLZ/CTZ (aka undefined
at zero) until the ubsan pass is done.
Now, we don't have PROP_ubsan and am not sure it is worth adding it,
there is PROP_ssa set by the ssa pass which is 3 passes before
ubsan, but there are only 2 warning passes in between, so PROP_ssa
looked good enough to me.

2024-12-12  Jakub Jelinek  <jakub@redhat.com>

	PR sanitizer/115127
	* match.pd (clz (X) == C, ctz (X) == C, ctz (X) >= C): Don't
	optimize if -fsanitize=builtin and not yet in SSA form.

	* c-c++-common/ubsan/builtin-2.c: New test.