strip: Treat "default" output_target as unspecified

Treat output target as unspecified if it is set to "default".

binutils/

	PR binutils/33230
	* objcopy.c (copy_file): Treat "default" output_target as
	unspecified.

binutils/testsuite/

	PR binutils/33230
	* binutils-all/x86-64/x86-64.exp (run_pr33230_test): New.
	Run binutils/33230 tests with readelf if supported.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
2 files changed