Don't allow statement-nodes in expression contexts.

lib/compiler/implementation/ssa/tracer.dart

Index: lib/compiler/implementation/ssa/tracer.dart
diff --git a/lib/compiler/implementation/ssa/tracer.dart b/lib/compiler/implementation/ssa/tracer.dart
index 8f543d4784576876550d0342287751c3ce97f2b3..ed46a98b0a18dad8745f17f0dea3d71ca8d19015 100644
--- a/lib/compiler/implementation/ssa/tracer.dart
+++ b/lib/compiler/implementation/ssa/tracer.dart
@@ -243,12 +243,14 @@ class HInstructionStringifier implements HVisitor<String> {
   String visitExit(HExit node) => "exit";
 
   String visitFieldGet(HFieldGet node) {
-    return 'get ${temporaryId(node.receiver)}';
+    String fieldName = node.element.name.slowToString();
+    return 'get ${temporaryId(node.receiver)}.$fieldName';
   }
 
   String visitFieldSet(HFieldSet node) {
     String valueId = temporaryId(node.value);
-    return 'set ${temporaryId(node.receiver)} to $valueId';
+    String fieldName = node.element.name.slowToString();
+    return 'set ${temporaryId(node.receiver)}.$fieldName to $valueId';
   }
 
   String visitLocalGet(HLocalGet node) => visitFieldGet(node);