[Driver] Update FIXME comment now that PR4941 has been addressed.

The actual fix should be addressed by someone who can test on Darwin.

llvm-svn: 258813
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index e9ccc05..faec8a1 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -5474,7 +5474,7 @@
 
 // Default to -fno-builtin-str{cat,cpy} on Darwin for ARM.
 //
-// FIXME: This is disabled until clang -cc1 supports -fno-builtin-foo. PR4941.
+// FIXME: Now that PR4941 has been fixed this can be enabled.
 #if 0
   if (getToolChain().getTriple().isOSDarwin() &&
       (getToolChain().getArch() == llvm::Triple::arm ||