PR c++/23333
	* include/cpplib.h: Add PURE_ZERO to flags for the cpp_token structure.

	* c-lex.c (c_lex_with_flags): Add PURE_ZERO to cpp_flags if
	number is a single digit '0'.

	* parser.c (cp_parser_pure_specifier): Check for PURE_ZERO to
	identify a single '0'.

	* g++.dg/parse/error25.C: Add more tests.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@108947 138bc75d-0d04-0410-961f-82ee72b054a4