Bump analyzer to 0.27.4-alpha.17.

* Support for trailing commas in parameter and argument lists (#26647).
* Strong mode breaking change: can now infer generic type arguments from the constructor invocation arguments (#25220).

BUG=
[email protected]

Review URL: https://codereview.chromium.org/2163503002 .

Author: pq

pkg/analyzer/CHANGELOG.md

@@ -1,4 +1,5 @@
-## Next release
+## 0.27.4-alpha.17 
+* Support for trailing commas in parameter and argument lists (#26647).
 * Strong mode breaking change: can now infer generic type arguments from the constructor invocation arguments (#25220).
 
 ## 0.27.4-alpha.16

pkg/analyzer/pubspec.yaml

@@ -1,5 +1,5 @@
 name: analyzer
-version: 0.27.4-alpha.16
+version: 0.27.4-alpha.17
 author: Dart Team <[email protected]>
 description: Static analyzer for Dart.
 homepage: https://github.com/dart-lang/sdk/tree/master/pkg/analyzer