Turn on -momit-leaf-frame-pointer by default on all non-Darwin platforms.
Fixes PR9121!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124718 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 8f8c64d..a253638 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1089,9 +1089,10 @@
     CmdArgs.push_back(A->getValue(Args));
   }
 
-  // -mno-omit-leaf-frame-pointer is default.
+  // -mno-omit-leaf-frame-pointer is the default on Darwin.
   if (Args.hasFlag(options::OPT_momit_leaf_frame_pointer,
-                   options::OPT_mno_omit_leaf_frame_pointer, false))
+                   options::OPT_mno_omit_leaf_frame_pointer,
+                   getToolChain().getTriple().getOS() != llvm::Triple::Darwin))
     CmdArgs.push_back("-momit-leaf-frame-pointer");
 
   // -fno-math-errno is default.