Fix some ldscripts/pr24008 fails

Fix some ldscripts/pr24008 fails

These targets were all failing due to extra symbols.
pdp11-dec-aout  +FAIL: ld-scripts/pr24008
powerpc-aix5.1  +FAIL: ld-scripts/pr24008
powerpc-aix5.2  +FAIL: ld-scripts/pr24008
rs6000-aix4.3.3  +FAIL: ld-scripts/pr24008
rs6000-aix5.1  +FAIL: ld-scripts/pr24008
rs6000-aix5.2  +FAIL: ld-scripts/pr24008

Some fails remain, those I saw were segfaults or assertion fails that
indicate target bugs.

	PR ld/24008
	* testsuite/ld-scripts/pr24008.d: Pass with extra target
	defined symbols.