Implement MarkGCCard.

Change-Id: Ic004750a303897d33a5459a41ac60ac552926e07
diff --git a/src/compiler_llvm/method_compiler.h b/src/compiler_llvm/method_compiler.h
index 0bfdf5d..7a5d66f 100644
--- a/src/compiler_llvm/method_compiler.h
+++ b/src/compiler_llvm/method_compiler.h
@@ -260,6 +260,8 @@
 
 #undef GEN_INSN_ARGS
 
+  // GC card table helper function
+  void EmitMarkGCCard(llvm::Value* value, llvm::Value* target_addr);
 
   // Shadow frame helper function
   void EmitPopShadowFrame();