analyzer: handle more IFN_UBSAN_* as no-ops [PR118300]

analyzer: handle more IFN_UBSAN_* as no-ops [PR118300]

Previously the analyzer treated IFN_UBSAN_BOUNDS as a no-op, but
the other IFN_UBSAN_* were unrecognized and conservatively treated
as having arbitrary behavior.

Treat IFN_UBSAN_NULL and IFN_UBSAN_PTR also as no-ops, which should
make -fanalyzer behave better with -fsanitize=undefined.

gcc/analyzer/ChangeLog:
	PR analyzer/118300
	* kf.cc (class kf_ubsan_bounds): Replace this with...
	(class kf_ubsan_noop): ...this.
	(register_sanitizer_builtins): Use it to handle IFN_UBSAN_NULL,
	IFN_UBSAN_BOUNDS, and IFN_UBSAN_PTR as nop-ops.
	(register_known_functions): Drop handling of IFN_UBSAN_BOUNDS
	here, as it's now handled by register_sanitizer_builtins above.

gcc/testsuite/ChangeLog:
	PR analyzer/118300
	* gcc.dg/analyzer/ubsan-pr118300.c: New test.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>