finally found the gcc defined constants

llvm-svn: 22502
diff --git a/llvm/lib/Target/Alpha/AlphaJITInfo.cpp b/llvm/lib/Target/Alpha/AlphaJITInfo.cpp
index ff09f09..c2074ff 100644
--- a/llvm/lib/Target/Alpha/AlphaJITInfo.cpp
+++ b/llvm/lib/Target/Alpha/AlphaJITInfo.cpp
@@ -51,7 +51,7 @@
 //static AlphaJITInfo* AlphaJTI;
 
 extern "C" {
-#if 0
+#ifdef __alpha
 
   void AlphaCompilationCallbackC(long* oldsp)
   {