PR preprocessor/37324
	* lib/target-supports.exp
	(check_effective_target_wchar_t_char16_t_compatible,
	check_effective_target_wchar_t_char32_t_compatible): New.
	* gcc.dg/utf-array.c: Use __CHAR{16,32}_TYPE__ macros in typedefs.
	Only require from incompatible errors for char{16,32}_t vs. wchar_t
	initializations if those types are indeed incompatible.

From-SVN: r140421