testsuite: aix testsuite adjustments

testsuite: aix testsuite adjustments

This patch re-enables the DWARF5 tests that seem to be functioning again.
It adds a comment to pr41445-7.c that any changes in lines need to be
reflected in the expected output.

The patch also allows for additional failures in ucs.c and reflects that
builtin-sprintf-warn-20.c requires 4 byte wide char support.

gcc/testsuite/ChangeLog:

	* gcc.dg/cpp/ucs.c: Expect Invalid warning for 2byte wchar.
	* gcc.dg/debug/dwarf2/inline6.c: Remove skip AIX.
	* gcc.dg/debug/dwarf2/lang-c11.c: Remove skip AIX.
	* gcc.dg/debug/dwarf2/pr41445-7.c: Remove skip AIX.
	* gcc.dg/debug/dwarf2/pr41445-8.c: Remove skip AIX.
	* gcc.dg/tree-ssa/builtin-sprintf-warn-20.c: Require 4byte wchar.