include function name in dot filename

Differential Revision: http://reviews.llvm.org/D29975

llvm-svn: 295220
diff --git a/llvm/lib/CodeGen/MachineBlockPlacement.cpp b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
index 8a57f00..bfc90e0 100644
--- a/llvm/lib/CodeGen/MachineBlockPlacement.cpp
+++ b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
@@ -2381,7 +2381,7 @@
   if (ViewBlockLayoutWithBFI != GVDT_None &&
       (ViewBlockFreqFuncName.empty() ||
        F->getFunction()->getName().equals(ViewBlockFreqFuncName))) {
-    MBFI->view(false);
+    MBFI->view("MBP." + MF.getName(), false);
   }