Prune BFD warnings for unknown GNU properties

Prune BFD warnings for unknown GNU properties

When glibc is enabled with the new GNU_PROPERTY_X86_XXX bits:

https://groups.google.com/forum/#!topic/x86-64-abi/-D05GQ3kWrA

BFD will issue an unknown GNU property warning like

warning: tmpdir/ld1: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0010001

and ignore such GNU properties.  This patch adds prune_warnings_extra to
prune such warnings on release branches and updates prune_warnings to
call prune_warnings_extra.

binutils/

	PR ld/23536
	* Makefile.am (development.exp): New target.
	(EXTRA_DEJAGNU_SITE_CONFIG): New.
	(DISTCLEANFILES): Add development.exp.
	* Makefile.in: Regenerated.
	* testsuite/binutils-all/objcopy.exp (strip_test): Call
	prune_warnings to prune BFD output.
	(strip_test_with_saving_a_symbol): Likewise.
	(objcopy_test_without_global_symbol): Likewise.
	* testsuite/lib/binutils-common.exp (prune_warnings_extra):
	New proc.
	(prune_warnings): Likewise.

gas/

	PR ld/23536
	* Makefile.am (development.exp): New target.
	(EXTRA_DEJAGNU_SITE_CONFIG): New.
	(DISTCLEANFILES): Add development.exp.
	* Makefile.in: Regenerated.

ld/

	PR ld/23536
	* Makefile.am (development.exp): New target.
	(EXTRA_DEJAGNU_SITE_CONFIG): New.
	(DISTCLEANFILES): Add development.exp.
	* Makefile.in: Regenerated.
	* testsuite/ld-bootstrap/bootstrap.exp: Call prune_warnings to
	prune BFD output.
	* testsuite/ld-plugin/lto.exp: Likewise.
	* testsuite/lib/ld-lib.exp (prune_warnings): Removed.
	* testsuite/ld-elf/shared.exp: Allow "\n" in linker warnings.