jni: Add @CriticalNative optimization to speed up JNI transitions

Change-Id: I963059ac3a72dd8e6a867596c356d7062deb6da7
diff --git a/runtime/well_known_classes.cc b/runtime/well_known_classes.cc
index 2c99275..5f5fbc8 100644
--- a/runtime/well_known_classes.cc
+++ b/runtime/well_known_classes.cc
@@ -30,6 +30,7 @@
 namespace art {
 
 jclass WellKnownClasses::com_android_dex_Dex;
+jclass WellKnownClasses::dalvik_annotation_optimization_CriticalNative;
 jclass WellKnownClasses::dalvik_annotation_optimization_FastNative;
 jclass WellKnownClasses::dalvik_system_DexFile;
 jclass WellKnownClasses::dalvik_system_DexPathList;
@@ -216,6 +217,8 @@
 
 void WellKnownClasses::Init(JNIEnv* env) {
   com_android_dex_Dex = CacheClass(env, "com/android/dex/Dex");
+  dalvik_annotation_optimization_CriticalNative =
+      CacheClass(env, "dalvik/annotation/optimization/CriticalNative");
   dalvik_annotation_optimization_FastNative = CacheClass(env, "dalvik/annotation/optimization/FastNative");
   dalvik_system_DexFile = CacheClass(env, "dalvik/system/DexFile");
   dalvik_system_DexPathList = CacheClass(env, "dalvik/system/DexPathList");