configure, Darwin: Recognise new naming for Xcode ld.

The latest editions of XCode have altered the identify reported by 'ld -v'
(again).  This means that GCC configure no longer detects the version.

Fixed by adding the new name to the set checked.

gcc/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Recognise PROJECT:ld-mmmm.nn.aa as an identifier
	for Darwin's static linker.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>