Fix a bug I introduced yesterday, which broke functions with *no* arguments.

llvm-svn: 28326
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 3c4dd2b..1971ada 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -542,6 +542,9 @@
     }
     FormalArgs.push_back(ArgValue);
   }
+  // Provide a chain.  Note that this isn't the right one, but it works as well
+  // as before.
+  FormalArgs.push_back(DAG.getEntryNode());
 }
 
 std::pair<SDOperand, SDOperand>
@@ -1081,6 +1084,10 @@
     }
     FormalArgs.push_back(ArgValue);
   }
+
+  // Provide a chain.  Note that this isn't the right one, but it works as well
+  // as before.
+  FormalArgs.push_back(DAG.getEntryNode());
 }
 
 std::pair<SDOperand, SDOperand>