* doc/c-tree.texi, doc/cpp.texi, doc/extend.texi,
	doc/frontends.texi, doc/gcov.texi, doc/gty.texi, doc/install.texi,
	doc/invoke.texi, doc/libgcc.texi, doc/md.texi, doc/rtl.texi,
	doc/sourcebuild.texi, doc/standards.texi, doc/tm.texi,
	doc/trouble.texi: Remove trailing whitespace.

From-SVN: r76098