extend.texi (Extended Asm): Clarify memory clobber.

2004-01-21  Andreas Jaeger  <aj@suse.de>
	    Michael Matz  <matz@suse.de>

	* doc/extend.texi (Extended Asm): Clarify memory clobber.

Co-Authored-By: Michael Matz <matz@suse.de>

From-SVN: r76288