Add vregs to ShadowFrame.

Change-Id: I870ab3c19c0e727f0e67b570eb55d45c3497d2ad
diff --git a/src/compiler_llvm/method_compiler.h b/src/compiler_llvm/method_compiler.h
index 15b8558..0b6fcfd 100644
--- a/src/compiler_llvm/method_compiler.h
+++ b/src/compiler_llvm/method_compiler.h
@@ -475,7 +475,7 @@
   llvm::Value* old_shadow_frame_;
 
   llvm::Value* already_pushed_shadow_frame_;
-  uint32_t shadow_frame_size_;
+  uint16_t num_shadow_frame_refs_;
 
   uint16_t elf_func_idx_;
 };