Handle variable arguments for ARM/Mips/X86.

Expand va_arg LLVM instruction in a target-specific manner.

Change-Id: Iddf071b7f4026f003df2ad129fd940c506e9ec99
diff --git a/lib/AndroidBitcode/ARM/ARMABCCompilerDriver.h b/lib/AndroidBitcode/ARM/ARMABCCompilerDriver.h
index ff1c91e..29f4f0a 100644
--- a/lib/AndroidBitcode/ARM/ARMABCCompilerDriver.h
+++ b/lib/AndroidBitcode/ARM/ARMABCCompilerDriver.h
@@ -27,6 +27,9 @@
       : ABCCompilerDriver(pTriple) { }
 
   virtual ~ARMABCCompilerDriver() { }
+
+private:
+  virtual ABCExpandVAArgPass *createExpandVAArgPass() const;
 };
 
 } // end namespace bcc