Allow private methods in interfaces.

Private methods may be generated in interfaces during compilation of
some default methods.  Change the verifier to allow these methods.

Bug: 27999840

Change-Id: Ib8120a8f6cb036021334d9af0ed78ae372974ecb
diff --git a/runtime/dex_file.h b/runtime/dex_file.h
index 3a28422..ce7f62a 100644
--- a/runtime/dex_file.h
+++ b/runtime/dex_file.h
@@ -57,6 +57,7 @@
 // TODO: move all of the macro functionality into the DexCache class.
 class DexFile {
  public:
+  static const uint32_t kDefaultMethodsVersion = 37;
   static const uint8_t kDexMagic[];
   static constexpr size_t kNumDexVersions = 2;
   static constexpr size_t kDexVersionLen = 4;