Update LLVM for 3.5 rebase (r209712).

Change-Id: I149556c940fb7dc92d075273c87ff584f400941f
diff --git a/lib/CodeGen/CallingConvLower.cpp b/lib/CodeGen/CallingConvLower.cpp
index fcfc9dc..add861a 100644
--- a/lib/CodeGen/CallingConvLower.cpp
+++ b/lib/CodeGen/CallingConvLower.cpp
@@ -76,7 +76,7 @@
       dbgs() << "Formal argument #" << i << " has unhandled type "
              << EVT(ArgVT).getEVTString() << '\n';
 #endif
-      llvm_unreachable(0);
+      llvm_unreachable(nullptr);
     }
   }
 }
@@ -108,7 +108,7 @@
       dbgs() << "Return operand #" << i << " has unhandled type "
              << EVT(VT).getEVTString() << '\n';
 #endif
-      llvm_unreachable(0);
+      llvm_unreachable(nullptr);
     }
   }
 }
@@ -126,7 +126,7 @@
       dbgs() << "Call operand #" << i << " has unhandled type "
              << EVT(ArgVT).getEVTString() << '\n';
 #endif
-      llvm_unreachable(0);
+      llvm_unreachable(nullptr);
     }
   }
 }
@@ -145,7 +145,7 @@
       dbgs() << "Call operand #" << i << " has unhandled type "
              << EVT(ArgVT).getEVTString() << '\n';
 #endif
-      llvm_unreachable(0);
+      llvm_unreachable(nullptr);
     }
   }
 }
@@ -162,7 +162,7 @@
       dbgs() << "Call result #" << i << " has unhandled type "
              << EVT(VT).getEVTString() << '\n';
 #endif
-      llvm_unreachable(0);
+      llvm_unreachable(nullptr);
     }
   }
 }
@@ -175,6 +175,6 @@
     dbgs() << "Call result has unhandled type "
            << EVT(VT).getEVTString() << '\n';
 #endif
-    llvm_unreachable(0);
+    llvm_unreachable(nullptr);
   }
 }