[patch]: Add push_macro/pop_macro feature for all targets by moving it from C frontent into libcpp

[Tom Tromey]

>>>>> "Kai" == Kai Tietz <ktietz70@googlemail.com> writes:

Kai> ChangeLog for libcpp
Kai> 2009-11-03  Kai Tietz  <kai.tietz@onevision.com>
Kai> 	* directives.c (do_pragma_push_macro): New pragma handler.
Kai> 	(do_pragma_pop_macro): Likewise.
Kai> 	(_cpp_init_internal_pragmas): Add push_macro and
Kai> 	pop_macro handler to internal pragmas.
Kai> 	(lex_macro_node_from_str): Removed.
Kai> 	(cpp_push_definition): Replace lex_macro_node_from_str
Kai> 	by _cpp_lex_identifier.
Kai> 	(cpp_pop_definition): Likewise.
Kai> 	* internal.h (_cpp_lex_identifier): New prototype.
Kai> 	(def_pragma_macro): New structure.
Kai> 	(cpp_reader): New member pushed_macros.
Kai> 	* lex.c (_cpp_lex_identifier): New function.
Kai> 	(lex_identifier_intern): New function.
Kai> 	* init.c (cpp_create_reader): Initialize pushed_macros
Kai> 	member.
Kai> 	(cpp_destroy): Free elements in pushed_macros member.
Kai> 	* pch.c (_cpp_save_pushed_macros): New function.
Kai> 	(_cpp_restore_pushed_macros): Likewise.
Kai> 	(_cpp_restore_pushed_macros): Use _cpp_save_pushed_macros.
Kai> 	(cpp_read_state): Use _cpp_restore_pushed_macros.

The libcpp parts are ok.

I can't approve the other bits.

Tom