Fix for 'await' highlighting in for-each.

pkg/analysis_server/lib/src/computer/computer_highlights.dart

Index: pkg/analysis_server/lib/src/computer/computer_highlights.dart
diff --git a/pkg/analysis_server/lib/src/computer/computer_highlights.dart b/pkg/analysis_server/lib/src/computer/computer_highlights.dart
index 50c51711b0860038aa8af4238c2ab715f56238fe..df2f5b538faca0de725f28507ddcc6ad6b759781 100644
--- a/pkg/analysis_server/lib/src/computer/computer_highlights.dart
+++ b/pkg/analysis_server/lib/src/computer/computer_highlights.dart
@@ -476,6 +476,7 @@ class _DartUnitHighlightsComputerVisitor extends RecursiveAstVisitor<Object> {
 
   @override
   Object visitForEachStatement(ForEachStatement node) {
+    computer._addRegion_token(node.awaitKeyword, HighlightRegionType.BUILT_IN);
     computer._addRegion_token(node.forKeyword, HighlightRegionType.KEYWORD);
     computer._addRegion_token(node.inKeyword, HighlightRegionType.KEYWORD);
     return super.visitForEachStatement(node);