ART: Fix type parameter in tests

Move Class to Class<?>, Constructor to Constructor<?>, and in
general clean up reflection.

Test: m test-art-host-run-test
Change-Id: I3a4223ee8d14d032015edf34bf27135757f7138c
diff --git a/test/125-gc-and-classloading/src/Main.java b/test/125-gc-and-classloading/src/Main.java
index 61e123d..e81ef7b 100644
--- a/test/125-gc-and-classloading/src/Main.java
+++ b/test/125-gc-and-classloading/src/Main.java
@@ -57,7 +57,7 @@
         public void run() {
             try {
                 cdl.await();
-                Class c0 = Class.forName("Main$BigClass");
+                Class<?> c0 = Class.forName("Main$BigClass");
             } catch (Exception e) {
                 throw new RuntimeException(e);
             }