Upgrade to the debug version of ASM, which includes generic signatures

and fix unnecessary casts.

MOE_MIGRATED_REVID=136857315
diff --git a/pom.xml b/pom.xml
index 9e26ce3..ddec737 100644
--- a/pom.xml
+++ b/pom.xml
@@ -37,14 +37,8 @@
     </dependency>
     <dependency>
       <groupId>org.ow2.asm</groupId>
-      <artifactId>asm</artifactId>
-      <version>5.0.3</version>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.ow2.asm</groupId>
-      <artifactId>asm-util</artifactId>
-      <version>5.0.3</version>
+      <artifactId>asm-debug-all</artifactId>
+      <version>5.1</version>
       <scope>test</scope>
     </dependency>
     <dependency>