A mutation that changes the length of an array.

This mutation takes an array and changes its length.

Test: ran dexfuzz until the mutation kicked in and used dexdump2 to find
the diff.
Change-Id: I5078b678673af7a839208c79113f1c1f26090baa
diff --git a/tools/dexfuzz/README b/tools/dexfuzz/README
index 58f6226..271ac2b 100644
--- a/tools/dexfuzz/README
+++ b/tools/dexfuzz/README
@@ -138,6 +138,7 @@
 InstructionDuplicator 80
 InstructionSwapper 80
 InvokeChanger 30
+NewArrayLengthChanger 50
 NewMethodCaller 10
 NonsenseStringPrinter 10
 OppositeBranchChanger 40