PR target/10301

	* config.gcc: Accept opteron and athlon-64 as variants
	of k8.
	* i386.c (override_options): Likewise.
	* invoke.texi (i386 -mtune): Expand documentation.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@75476 138bc75d-0d04-0410-961f-82ee72b054a4