fix tests. Rebinding for 'def' reference should do nothing because it references to an inferred variable's type or to a variable itself.

plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/impl/statements/GrVariableDeclarationImpl.java

@@ -242,6 +242,11 @@ public class GrVariableDeclarationImpl extends GrStubElementBase<EmptyStub> impl
         public Object[] getVariants() {
           return EMPTY_ARRAY;
         }
+
+        @Override
+        public PsiElement bindToElement(@NotNull PsiElement element) throws IncorrectOperationException {
+          return getElement();
+        }
       };
     }
     else {
@@ -257,6 +262,11 @@ public class GrVariableDeclarationImpl extends GrStubElementBase<EmptyStub> impl
         public Object[] getVariants() {
           return EMPTY_ARRAY;
         }
+
+        @Override
+        public PsiElement bindToElement(@NotNull PsiElement element) throws IncorrectOperationException {
+          return getElement();
+        }
       };
     }
   }