Adjust hwasan testcase for x86 target.

There're 2 cases:
1. hwasan-poison-optimisation.c is supposed to scan call to
__hwasan_tag_mismatch4, and x86 have different mnemonic(call) from
aarch64(bl), so adjust testcase to scan either call or bl.

2. alloca-outside-caught.c/vararray-outside-caught.c are supposed to
scan mismatched tags and expected the tag corresponding to
out-of-bounds memory is 00, but for x86 the continous stack is
allocated by other local variable/array which is assigned with a
different tag, but still there're mismatches. So adjust testcase to
scan XX/XX instead of XX/00.

gcc/testsuite/ChangeLog:

	* c-c++-common/hwasan/alloca-outside-caught.c: Adjust
	testcase.
	* c-c++-common/hwasan/hwasan-poison-optimisation.c: Ditto.
	* c-c++-common/hwasan/vararray-outside-caught.c: Ditto.