build: Allow for Xcode 15 ld -v output

build: Allow for Xcode 15 ld -v output

Since Xcode 15 beta 6, ld -v output differs from previous versions:

* macOS 13/Xcode 14:

  @(#)PROGRAM:ld  PROJECT:ld64-857.1

* macOS 14/Xcode 15:

  @(#)PROGRAM:ld  PROJECT:dyld-1015.1

configure cannot handle the new form, so LD64_VERSION isn't set.

This patch fixes this.  The autoconf manual states that sed doesn't
portably support alternation, so I'm using two separate expressions to
extract the version number.

Tested on x86_64-apple-darwin23.0.0.

2023-08-16  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gcc:
	* configure.ac (gcc_cv_ld64_version): Allow for dyld in ld -v
	output.
	* configure: Regenerate.