Add UNDEFINED_HIDDEN_NAME, UNDEFINED_SHOWN_NAME

pkg/analyzer/lib/src/generated/element_resolver.dart

Index: pkg/analyzer/lib/src/generated/element_resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/element_resolver.dart b/pkg/analyzer/lib/src/generated/element_resolver.dart
index e8591ae18030be357572764b52393c0539bb8113..af56ce87ebe7b083cfc4c9eccb7ac80ae2375e76 100644
--- a/pkg/analyzer/lib/src/generated/element_resolver.dart
+++ b/pkg/analyzer/lib/src/generated/element_resolver.dart
@@ -2088,7 +2088,15 @@ class ElementResolver extends SimpleAstVisitor<Object> {
         if (element == null) {
           element = namespace.get("$nameStr=");
         }
-        if (element != null) {
+        if (element == null) {
+          ErrorCode hintCode;

[Brian Wilkerson, 2016/04/19 14:07:32]

I would prefer to have the hint generation moved to the code that generates the
majority of the hints (can't remember the class name at the moment, but I can
look it up if you'd like). (I'd actually like to remove all hint and error
generation from this class for performance reasons.)

[Brian Wilkerson, 2016/04/20 18:09:57]

To follow up: turns out I couldn't remember because it doesn't exist. Hints are
generated by several classes, but the most appropriate would be
DeadCodeVerifier.

[srawlins, 2016/04/20 20:34:01]

Done.

+          if (combinator is HideCombinator) {
+            hintCode = HintCode.UNDEFINED_HIDDEN_NAME;
+          } else {
+            hintCode = HintCode.UNDEFINED_SHOWN_NAME;
+          }
+          _recordUndefinedNode(null /*declaringElement*/, hintCode, name, [nameStr]);
+        } else {
           // Ensure that the name always resolves to a top-level variable
           // rather than a getter or setter
           if (element is PropertyAccessorElement) {