Bump oat version.

Two recent changes should have bumped the oat version but
they did not:
    https://android-review.googlesource.com/336161
    https://android-review.googlesource.com/338409

Test: Rely on Treehugger.
Change-Id: I105f2f2d54953ed808ded92234c06efcc155d313
diff --git a/runtime/oat.h b/runtime/oat.h
index a764e0e..0f6657b 100644
--- a/runtime/oat.h
+++ b/runtime/oat.h
@@ -32,7 +32,7 @@
 class PACKED(4) OatHeader {
  public:
   static constexpr uint8_t kOatMagic[] = { 'o', 'a', 't', '\n' };
-  static constexpr uint8_t kOatVersion[] = { '1', '1', '1', '\0' };  // Revert^3 hash-based DexCache types.
+  static constexpr uint8_t kOatVersion[] = { '1', '1', '2', '\0' };  // Manual bump (Revert^3 hash-based DexCache types; stack maps).
 
   static constexpr const char* kImageLocationKey = "image-location";
   static constexpr const char* kDex2OatCmdLineKey = "dex2oat-cmdline";