Revert changes to JasminBuilder

Change-Id: Ife709a13d02a620762c7323c714015b2fcc7c330

src/test/java/com/android/tools/r8/jasmin/JasminBuilder.java

diff --git a/src/test/java/com/android/tools/r8/jasmin/JasminBuilder.java b/src/test/java/com/android/tools/r8/jasmin/JasminBuilder.java
index 7070667..26f2030 100644
--- a/src/test/java/com/android/tools/r8/jasmin/JasminBuilder.java
+++ b/src/test/java/com/android/tools/r8/jasmin/JasminBuilder.java
@@ -102,18 +102,17 @@
     }
 
     private ClassBuilder(String name, String superName, String... interfaces) {
-      assert DescriptorUtils.isValidJavaType(name);
       this.name = name;
       this.superName = superName;
       this.interfaces = ImmutableList.copyOf(interfaces);
     }
 
     public String getSourceFile() {
-      return DescriptorUtils.getBinaryNameFromJavaType(name) + ".j";
+      return name + ".j";
     }
 
     public String getDescriptor() {
-      return DescriptorUtils.javaTypeToDescriptor(name);
+      return "L" + name + ";";
     }
 
     public MethodSignature addAbstractMethod(