* config.gcc (rs6000-ibm-aix[5-9]*): Change to aix51.h.
	* collect2.c (main): Delete importf.  Add ".obj" file extension.
	(GCC_CHECK_HDR): Handle AIX V5 new magic number.
	(aix_std_libs): Add additional AIX libraries to skip.
	* config/rs6000/aix.h (MY_ISCOFF): Add AIX V5 new magic number.
	* config/rs6000/aix51.h: New file.

From-SVN: r39271