Auto merge of #3772 - flip1995:ice-3719, r=Manishearth

Auto merge of #3772 - flip1995:ice-3719, r=Manishearth

Fix ICE #3719+#3718 in lint match_ref_pats

Fixes #3719
This conveniently also fixes #3718

The ICE occurs when the match expression was a macro call, where the macro was defined in another file. Since we don't have the ability to reproduce this behavior with our UI tests (AFAIK), I couldn't add a test reproducing this ICE.. However, I added a test which is related to the ICE, to show the new behavior of the lint.

I tested it with the mscheme repo locally and the ICE didn't happen anymore.

r? @matthiaskrgr