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/472-unreachable-if-regression/src/Main.java b/test/472-unreachable-if-regression/src/Main.java
index c9f9511..d426df1 100644
--- a/test/472-unreachable-if-regression/src/Main.java
+++ b/test/472-unreachable-if-regression/src/Main.java
@@ -25,12 +25,12 @@
     System.out.println("Test started.");
     Class<?> c = Class.forName("Test");
 
-    Method unreachableIf = c.getMethod("UnreachableIf", (Class[]) null);
-    unreachableIf.invoke(null, (Object[]) null);
+    Method unreachableIf = c.getMethod("UnreachableIf");
+    unreachableIf.invoke(null);
     System.out.println("Successfully called UnreachableIf().");
 
-    Method unreachablePackedSwitch = c.getMethod("UnreachablePackedSwitch", (Class[]) null);
-    unreachablePackedSwitch.invoke(null, (Object[]) null);
+    Method unreachablePackedSwitch = c.getMethod("UnreachablePackedSwitch");
+    unreachablePackedSwitch.invoke(null);
     System.out.println("Successfully called UnreachablePackedSwitch().");
   }