* doc/compat.texi, doc/cpp.texi, doc/cppopts.texi,
	doc/extend.texi, doc/install.texi, doc/invoke.texi,
	doc/sourcebuild.texi, doc/tm.texi, doc/tree-ssa.texi,
	doc/trouble.texi: Use @option around options.

From-SVN: r87635