config.gcc (powerpc*-*-*): Add support for a new configure option --with-advance-toolchain=<xxx> which...

2015-06-03  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* config.gcc (powerpc*-*-*): Add support for a new configure
	option --with-advance-toolchain=<xxx> which overrides using the
	default header files, libraries and dynamic linker.

	* config/rs6000/linux64.h (SUBSUBTARGET_EXTRA_SPECS): Add new
	specs to support the configure --with-advance-toolchain=<xxx>
	option.
	(INCLUDE_EXTRA_SPEC): Likewise.
	(LINK_OS_EXTRA_SPEC32): Likewise.
	(LINK_OK_EXTRA_SPEC64): Likewise.
	(LINK_OS_NEW_DTAGS_SPEC): Likewise.
	(DYNAMIC_LINKER_PREFIX): Likewise.
	(CPP_OS_DEFAULT_SPEC): Use the new specs for providing advance
	toolchain support.
	(GLIBC_DYNAMIC_LINKER32): Likewise.
	(GLIBC_DYNAMIC_LINKER64): Likewise.
	(LINK_OS_LINUX_SPEC32): Likewise.
	(LINK_OS_LINUX_SPEC64): Likewise.

	* doc/install.texi (--enable-advance-toolchain=<xx>): Document new
	configuration option.

From-SVN: r224095