Merge branch 'rust-lang:master' into master

Author: c4rrao

.github/ISSUE_TEMPLATE/tracking_issue.md

@@ -28,6 +28,8 @@ Tracking issues are used to record the overall progress of implementation.
 They are also used as hubs connecting to other relevant issues, e.g., bugs or open design questions.
 A tracking issue is however *not* meant for large scale discussion, questions, or bug reports about a feature.
 Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.
+Discussion comments will get marked as off-topic or deleted.
+Repeated discussions on the tracking issue may lead to the tracking issue getting locked.
 
 ### Steps
 <!--

.github/pull_request_template.md

@@ -0,0 +1,10 @@
+<!--
+If this PR is related to an unstable feature or an otherwise tracked effort,
+please link to the relevant tracking issue here. If you don't know of a related
+tracking issue or there are none, feel free to ignore this.
+
+This PR will get automatically assigned to a reviewer. In case you would like
+a specific user to review your work, you can assign it to them by using
+
+    r​? <reviewer name>
+-->