Version 1.17.0-dev.6.4

Cherry-pick '88dd7c8f37c5c51591e0c629d1f9e09599f7339f' to dev

Author: whesse

pkg/compiler/lib/src/util/link_implementation.dart

@@ -61,7 +61,7 @@ class LinkEntry<T> extends Link<T> {
  Link<T> tail;
 
  LinkEntry(T this.head, [Link<T> tail])
- : this.tail = ((tail == null) ? new Link<T>() : tail);
+ : this.tail = ((tail == null) ? const Link() : tail);
 
  Link<T> prepend(T element) {
  // TODO(ahe): Use new Link<T>, but this cost 8% performance on VM.

tools/VERSION

@@ -28,4 +28,4 @@ MAJOR 1
 MINOR 17
 PATCH 0
 PRERELEASE 6
-PRERELEASE_PATCH 3
+PRERELEASE_PATCH 4