Fix span location to skip comments
Fix span location to skip comments

R=vsm@google.com

Review URL: https://chromereviews.googleplex.com/120837013

ronlobo/dev_compiler,ochafik/dev_compiler,ochafik/dev_compiler,ochafik/dev_compiler,ronlobo/dev_compiler,ronlobo/dev_compiler,ochafik/dev_compiler,ronlobo/dev_compiler