winnt-cxx.c (i386_pe_type_dllimport_p): Don't ignore dllimport attribute of virtual methods.

gcc
	* config/i386/winnt-cxx.c (i386_pe_type_dllimport_p): Don't ignore
	dllimport attribute of virtual methods.

gcc/cp
	* class.c (check_for_override): Don't remove dllmport attribute of
	virtual methods.

gcc/testsuite

	* g++.dg/ext/dllimport12.C: Update comments

From-SVN: r123492