Diagnose illegal lvalues better.

dart/sdk/lib/_internal/compiler/implementation/compiler.dart

Index: dart/sdk/lib/_internal/compiler/implementation/compiler.dart
diff --git a/dart/sdk/lib/_internal/compiler/implementation/compiler.dart b/dart/sdk/lib/_internal/compiler/implementation/compiler.dart
index a8ed28b8e66e16eddc4ac20f6cbdf38d81817e66..23f6302800cc4c169ae8f4eeff986bc54de26366 100644
--- a/dart/sdk/lib/_internal/compiler/implementation/compiler.dart
+++ b/dart/sdk/lib/_internal/compiler/implementation/compiler.dart
@@ -162,6 +162,7 @@ abstract class Compiler implements DiagnosticListener {
       if (!hasCrashed) {
         SourceSpan span = spanFromSpannable(ex.node);
         reportDiagnostic(span, ex.message, api.Diagnostic.ERROR);
+        pleaseReportCrash();
       }
       hasCrashed = true;
       throw;
@@ -304,6 +305,10 @@ abstract class Compiler implements DiagnosticListener {
     reportDiagnostic(spanFromElement(element),
                      MessageKind.COMPILER_CRASHED.error().toString(),
                      api.Diagnostic.CRASH);
+    pleaseReportCrash();
+  }
+
+  void pleaseReportCrash() {
     print(MessageKind.PLEASE_REPORT_THE_CRASH.message([BUILD_ID]));
   }