Don't forget to mark RAX as live-out of the function when arranging for
it to hold the address of an sret return value, for x86-64 ABI purposes.

Also, fix the test that was originally intended to test this to actually
test it, using FileCheck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83853 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index fb5399e..fadc818 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1162,6 +1162,9 @@
 
     Chain = DAG.getCopyToReg(Chain, dl, X86::RAX, Val, Flag);
     Flag = Chain.getValue(1);
+
+    // RAX now acts like a return value.
+    MF.getRegInfo().addLiveOut(X86::RAX);
   }
 
   RetOps[0] = Chain;  // Update chain.