Save R9 when up-call.

Thanks to Ian who found this bug. This change can also fix a jni_internal_test
on device when we use -O2 instead of -O0.

Change-Id: I38ac829409aeacb120f5b3d239aedcd39ec32e63
diff --git a/src/compiler_llvm/runtime_support_builder.h b/src/compiler_llvm/runtime_support_builder.h
index 7b54c69..8fd0d17 100644
--- a/src/compiler_llvm/runtime_support_builder.h
+++ b/src/compiler_llvm/runtime_support_builder.h
@@ -47,7 +47,7 @@
                                                 TBAASpecialType s_ty);
   virtual void EmitStoreToThreadOffset(int64_t offset, llvm::Value* value,
                                        TBAASpecialType s_ty);
-  virtual void EmitSetCurrentThread(llvm::Value* thread);
+  virtual llvm::Value* EmitSetCurrentThread(llvm::Value* thread);
 
   /* ShadowFrame */
   virtual llvm::Value* EmitPushShadowFrame(llvm::Value* new_shadow_frame,