libcpp/
	* lex.c (lex_string): Add -Wc++11-compat warning.
	* include/cpplib.h: Add CPP_W_CXX11_COMPAT.
	(struct cpp_options): Add cpp_warn_cxx11_compat.
	* init.c (cpp_create_reader): Initialize it.
gcc/c-family/
	* c.opt (Wc++0x-compat): Set it.

From-SVN: r222961