Auto merge of #37118 - alexcrichton:rollup, r=alexcrichton

Rollup of 17 pull requests

- Successful merges: #36762, #36831, #36973, #36991, #36995, #37023, #37049, #37050, #37056, #37064, #37066, #37067, #37084, #37089, #37091, #37092, #37110
- Failed merges:

lib.rs

@@ -295,7 +295,7 @@
 #![cfg_attr(not(stage0), deny(warnings))]
 
 #![feature(str_escape)]
-#![feature(question_mark)]
+#![cfg_attr(stage0, feature(question_mark))]
 
 use self::LabelText::*;