Implement codegen support for lowering "library builtins" like __builtin_isinf 
to their corresponding library routines (e.g. isinf).  This allows us to handle
all the stuff in macos math.h, and other stuff as it's added to *Builtins.def.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@41634 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CodeGen/CGExpr.cpp b/CodeGen/CGExpr.cpp
index 2981ed6..d175610 100644
--- a/CodeGen/CGExpr.cpp
+++ b/CodeGen/CGExpr.cpp
@@ -376,7 +376,10 @@
           return EmitBuiltinExpr(builtinID, E);
         
   llvm::Value *Callee = EmitScalarExpr(E->getCallee());
-  
+  return EmitCallExpr(Callee, E);
+}
+
+RValue CodeGenFunction::EmitCallExpr(llvm::Value *Callee, const CallExpr *E) {
   // The callee type will always be a pointer to function type, get the function
   // type.
   QualType CalleeTy = E->getCallee()->getType();