* lib/target_supports.exp (check_effective_target_4byte_wchar_t):
	New proc.
	* gcc.dg/utf16-4.c: Use it.
	* gcc.dg/utf32-4.c: Use it.
	* g++.dg/ext/utf16-4.C: Use it.
	* gcc.dg/ext/utf32-4.C: Use it.

From-SVN: r134971