do not rise conflict on type parameter rename ( IDEA-55362 )

java/java-impl/src/com/intellij/refactoring/rename/RenameJavaClassProcessor.java

@@ -217,7 +217,7 @@ public class RenameJavaClassProcessor extends RenamePsiElementProcessor {
         }
       }
     }
-    else {
+    else if (!(aClass instanceof PsiTypeParameter)) {
       final String qualifiedNameAfterRename = RenameUtil.getQualifiedNameAfterRename(aClass.getQualifiedName(), newName);
       Project project = element.getProject();
       final PsiClass conflictingClass =

java/java-tests/testData/refactoring/renameCollisions/RenameTypeParameterToExistingClassName.java

@@ -0,0 +1,3 @@
+public class Test<T<caret> extends String> {}
+
+class P {}

java/java-tests/testData/refactoring/renameCollisions/RenameTypeParameterToExistingClassName.java.after

@@ -0,0 +1,3 @@
+public class Test<P extends String> {}
+
+class P {}

java/java-tests/testSrc/com/intellij/refactoring/RenameCollisionsTest.java

@@ -157,6 +157,10 @@ public class RenameCollisionsTest extends LightCodeInsightTestCase {
     fail("Conflicts were not found");
   }
 
+  public void testRenameTypeParameterToExistingClassName() throws Exception {
+    doTest("P");
+  }
+
   private void doTest(final String newName) throws Exception {
     configureByFile(BASE_PATH + getTestName(false) + ".java");
     PsiElement element = TargetElementUtilBase