Use reference type from wrapped instruction in BaseRewrittenReferenceInstruction

Otherwise, the reference won't be rewritten correctly if the overriding
class overrides getReferenceType to return a different type.

dexlib2/src/main/java/org/jf/dexlib2/rewriter/InstructionRewriter.java

@@ -81,7 +81,7 @@ public class InstructionRewriter implements Rewriter<Instruction> {
         }
 
         @Override @Nonnull public Reference getReference() {
-            switch (getReferenceType()) {
+            switch (instruction.getReferenceType()) {
                 case ReferenceType.TYPE:
                     return RewriterUtils.rewriteTypeReference(rewriters.getTypeRewriter(),
                             (TypeReference)instruction.getReference());