Support IRgen of sqrt -> llvm.sqrt, pow -> llvm.pow.

 - Define pow[lf]?, sqrt[lf]? as builtins.

 - Add -fmath-errno option which binds to LangOptions.MathErrno

 - Add new builtin flag Builtin::Context::isConstWithoutErrno for
   functions which can be marked as const if errno isn't respected for
   math functions. Sema automatically marks these functions as const
   when they are defined, if MathErrno=0.

 - IRgen uses const attribute on sqrt and pow library functions to
   decide if it can use the llvm intrinsic.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64689 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 4dc8a9e..b151dd2 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -969,7 +969,7 @@
       if (const FunctionDecl *FDecl = 
           dyn_cast<const FunctionDecl>(DRExpr->getDecl()))
         if (unsigned builtinID = FDecl->getBuiltinID(getContext()))
-          return EmitBuiltinExpr(builtinID, E);
+          return EmitBuiltinExpr(FDecl, builtinID, E);
 
   if (E->getCallee()->getType()->isBlockPointerType())
     return EmitBlockCallExpr(E);