middle-end/125977 - disable RTL expansion ranger use at -O0

It wasn't the intention to enable it without optimizing, so disable it.

	PR middle-end/125977
	* cfgexpand.cc (pass_expand::execute): Guard ranger use
	on optimize.

(cherry picked from commit 4b99a9a276291e7b8d4d52b6a6da8e7016d8c588)
1 file changed