* cppinit.c: Include cppdefault.h.  Refer to
	cpp_GCC_INCLUDE_DIR and cpp_GCC_INCLUDE_DIR_len, not directly
	to GCC_INCLUDE_DIR and its length.
	(SIZE_TYPE, PTRDIFF_TYPE, WCHAR_TYPE,
	USER_LABEL_PREFIX, REGISTER_PREFIX, struct default_include,
	STANDARD_INCLUDE_DIR, STANDARD_INCLUDE_COMPONENT):  Move to
	cppdefault.h.
	(include_defaults_array): Move to cppdefault.c.

	* cppdefault.h: New file.
	* cppdefault.c: New file.

	* Makefile.in (LIBCPP_OBJS): Add cppdefault.o.
	(cppinit.o): Don't apply $(PREPROCESSOR_DEFINES) to this file.
	(cppdefault.o): New rule; apply $(PREPROCESSOR_DEFINES) to
	this file.

From-SVN: r34892