Enable tail call optimization in the presence of a byval (x86-32 and x86-64).
<rdar://problem/9483883>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133858 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 6c606be..bab15e6 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2505,6 +2505,10 @@
     if (!FINode)
       return false;
     FI = FINode->getIndex();
+  } else if (Arg.getOpcode() == ISD::FrameIndex && Flags.isByVal()) {
+    FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(Arg);
+    FI = FINode->getIndex();
+    Bytes = Flags.getByValSize();
   } else
     return false;