* decl.c (case_conversion): Detect narrowing in case values.

	* c-c++-common/pr89888.c: Update expected dg-error.
	* g++.dg/cpp0x/Wnarrowing17.C: New test.
	* g++.dg/cpp0x/enum28.C: Update expected dg-error.

From-SVN: r273976