re PR sanitizer/63956 ([UBSAN] ICE segfault in cxx_eval_call_expression ../../gcc...

re PR sanitizer/63956 ([UBSAN] ICE segfault in cxx_eval_call_expression ../../gcc/cp/constexpr.c)

	PR sanitizer/63956
	* ubsan.c (is_ubsan_builtin_p): Check also built-in class.
cp/
	* constexpr.c: Include ubsan.h.
	(cxx_eval_call_expression): Bail out for IFN_UBSAN_{NULL,BOUNDS}
	internal functions and for ubsan builtins.
	* error.c: Include internal-fn.h.
	(dump_expr): Add printing of internal functions.
testsuite/
	* c-c++-common/ubsan/shift-5.c: Add xfails.
	* g++.dg/ubsan/div-by-zero-1.C: Don't use -w.  Add xfail.
	* g++.dg/ubsan/pr63956.C: New test.

From-SVN: r218221