pr57793.c: Add expected error messages for targets with small integers.

pr57793.c: Add expected error messages for targets with small integers.

	* c-c++-common/pr57793.c: Add expected error messages for
	targets with small integers.
	* gcc.dg/c99-stdint-1.c: Only run on 32-bit plus targets.
	* gcc.dg/c99-stdint-2.c: Likewise.
	* gcc.dg/cdce1.c: Likewise.
	* gcc.dg/fold-overflow-1.c: Likewise.
	* gcc.dg/utf-cvt.c: Likewise.
	* gcc.dg/ftrapv-1.c: Only run on targets that support trapping
	arithmetic.
	* gcc.dg/ftrapv-2.c: Likewise.
	* gcc.dg/pr30286.c: Likewise.
	* gcc.dg/pr19340.c: Only run on targets that support
	scheduling.
	* lib/target-supports.exp (check_effective_target_trapping): New
	proc.  Returns true if the target supports trapping arithmetic.

From-SVN: r204053