Fix logic around determining use of frame pointer with -pg.

Summary:
As part of r342165, I rewrote the logic to check whether
-fno-omit-frame-pointer was passed after a -fomit-frame-pointer
argument. This CL switches that logic to use the consolidated
shouldUseFramePointer() function. This fixes a potential issue where -pg
gets used with -fomit-frame-pointer on a platform that must always retain
frame pointers.

Reviewers: dblaikie

Reviewed By: dblaikie

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D52191

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@342501 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Driver/ToolChains/Clang.cpp

@@ -4956,8 +4956,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   }
 
   if (Arg *A = Args.getLastArg(options::OPT_pg))
-    if (Args.hasFlag(options::OPT_fomit_frame_pointer,
-                     options::OPT_fno_omit_frame_pointer, /*default=*/false))
+    if (shouldUseFramePointer(Args, Triple))
       D.Diag(diag::err_drv_argument_not_allowed_with) << "-fomit-frame-pointer"
                                                       << A->getAsString(Args);