testsuite: Fix up pr111309-2.c on arm [PR111309]

testsuite: Fix up pr111309-2.c on arm [PR111309]

ARM defaults to -fshort-enums and the following testcase FAILs there in 2
lines.  The difference is that in C++, E0 has enum E type, which normally
has unsigned int underlying type, so it isn't int nor something that
promotes to int, which is why we diagnose it (in C it is promoted to int).
But with -fshort-enums, the underlying type is unsigned char in that case,
which promotes to int just fine.

The following patch adjusts the expectations, such that we don't expect
it on arm or when people manually test with -fshort-enums.

2023-11-21  Jakub Jelinek  <jakub@redhat.com>

	PR c/111309
	* c-c++-common/pr111309-2.c (foo): Don't expect errors for C++ with
	-fshort-enums if second argument is E0.