re PR target/35401 (libstdc++ linked to system /usr/lib/libgcc_s.1.dylib not new  gcc4.3 libgcc_s.1.dylib)

	PR target/35401
	* config/t-slibgcc-darwin: Make install-leaf dependent on
	install-darwin-libgcc-stubs instead of install.

From-SVN: r132819