allow darwin branch island control depening on system version

allow darwin branch island control depening on system version

	* config/i386/darwin.h: Define darwin_emit_branch_islands.
	(TARGET_MACHO_BRANCH_ISLANDS): New.
	(FUNCTION_PROFILER): Use TARGET_MACHO_BRANCH_ISLANDS.
	* config/i386/i386.h (TARGET_MACHO_BRANCH_ISLANDS): Define a
	default value.
	* config/i386/i386.c (output_pic_addr_const): Do not emit
	branch islands unless TARGET_MACHO_BRANCH_ISLANDS is set.
	(x86_output_mi_thunk): Adjust symbol creation.
	* config/rs6000/darwin.h: Define darwin_emit_branch_islands.
	Remove out of date comment.
	* config/rs6000/rs6000.c (print_operand): Adjust symbol.
	DARWIN_LINKER_GENERATES_ISLANDS: Remove.
	DARWIN_GENERATE_ISLANDS: Ditto.
	(output_call):  Do not emit branch islands unless
	darwin_emit_branch_islands is set.
	* config/darwin.c: Declare darwin_emit_branch_islands.
	(machopic_indirect_data_reference): Do not emit unless
	darwin_emit_branch_islands is set.
	(darwin_override_options): Set darwin_emit_branch_islands
	where it is needed.
	* config/darwin9.h
	DARWIN_LINKER_GENERATES_ISLANDS: Remove.

From-SVN: r162299