Patches from H.J. Lu for alpha-linux -fPIC --enable-shared problem.

	* Makefile.in (local-distclean): Also remove mh-frag mt-frag.
	* configure.in (skipdirs): Add target-librx for Linux.
	(alpha-*-linux*): Use config/mh-elfalphapic and config/mt-elfalphapic.
	* mh-elfalphapic, mt-elfalphapic: New files.

From-SVN: r15419