Cherry-pick CHANGELOG from analyzer 0.37.1+1.
Cherry-pick CHANGELOG from analyzer 0.37.1+1.

Analyzer 0.37.1+1 was just published from a branch.  We want the
CHANGELOG entries from the branch in master, so that when we later
release analyzer version 0.38.0, it will contain the CHANGELOG for
0.37.1+1.

Change-Id: I018e323c3b256c4b4b2dfe8120a82ba4b3ce0ced
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/113049
Auto-Submit: Paul Berry <72d414e3a99fb120308437779d51667bcc0984eb@google.com>
Reviewed-by: Brian Wilkerson <1f7641b6b14c52b9163524ab8d9aabff80176f21@google.com>
Commit-Queue: Paul Berry <72d414e3a99fb120308437779d51667bcc0984eb@google.com>

dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk