libcpp/
	* include/cpplib.h (NODE_CONDITIONAL): New.
	(struct cpp_callbacks): New macro_to_expand field.
	(struct cpp_hashnode): Adjust size of flags and type fields.
	(cpp_peek_token): Prototype.
	* lex.c (cpp_peek_token): New function.
	(_cpp_temp_token): Protect pre-existing lookaheads.
	* macro.c (cpp_get_token): Expand any conditional macros.
	(_cpp_backup_tokens_direct): New.
	(_cpp_backup_tokens): Call _cpp_backup_tokens_direct.
	(warn_of_redefinition): Silently allow redefined conditional
	macros.
	(_cpp_create_definition): Remove the conditional flag when a user
	defines one of the conditional macros.
	* internal.h (_cpp_backup_tokens_direct): New prototype.

gcc/
	* c-common.h (C_CPP_HASHNODE): New macro.
	* coretypes.h (struct cpp_token): Forward declare.
	* doc/extend.texi (PowerPC AltiVec Built-in Functions): Document
	the context-sensitive keyword method.
	* config/rs6000/rs6000-c.c (__vector_keyword, vector_keyword,
	__pixel_keyword, pixel_keyword, __bool_keyword, bool_keyword,
	expand_bool_pixel): New.
	(altivec_categorize_keyword): New function.
	(init_vector_keywords): New function.
	(rs6000_macro_to_expand): Likewise.
	(rs6000_cpu_cpp_builtins): Enable context-sensitive macros if not
	compiling an ISO C dialect.

gcc/testsuite/
	* gcc.target/powerpc/altivec-macros.c: New test.
	* gcc.target/powerpc/altviec-26.c: Likewise.
	* gcc.dg/vmx/1b-06.c: Remove bool variable.
	* gcc.dg/vmx/1b-07.c: Likewise.
	* gcc.dg/vmx/1b-06-ansi.c: New test for the pre-define method.
	* gcc.dg/vmx/1b-07-ansi.c: Likewise.

From-SVN: r137775