Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
diff --git a/clang/unittests/Driver/DistroTest.cpp b/clang/unittests/Driver/DistroTest.cpp
index bc1863c..d0c86d1 100644
--- a/clang/unittests/Driver/DistroTest.cpp
+++ b/clang/unittests/Driver/DistroTest.cpp
@@ -1,9 +1,8 @@
 //===- unittests/Driver/DistroTest.cpp --- ToolChains tests ---------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
diff --git a/clang/unittests/Driver/ModuleCacheTest.cpp b/clang/unittests/Driver/ModuleCacheTest.cpp
index 7340889..db3395f 100644
--- a/clang/unittests/Driver/ModuleCacheTest.cpp
+++ b/clang/unittests/Driver/ModuleCacheTest.cpp
@@ -1,9 +1,8 @@
 //===- unittests/Driver/ModuleCacheTest.cpp -------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
diff --git a/clang/unittests/Driver/MultilibTest.cpp b/clang/unittests/Driver/MultilibTest.cpp
index c5e8e09..9dca139 100644
--- a/clang/unittests/Driver/MultilibTest.cpp
+++ b/clang/unittests/Driver/MultilibTest.cpp
@@ -1,9 +1,8 @@
 //===- unittests/Driver/MultilibTest.cpp --- Multilib tests ---------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
diff --git a/clang/unittests/Driver/ToolChainTest.cpp b/clang/unittests/Driver/ToolChainTest.cpp
index f118107..80938c8 100644
--- a/clang/unittests/Driver/ToolChainTest.cpp
+++ b/clang/unittests/Driver/ToolChainTest.cpp
@@ -1,9 +1,8 @@
 //===- unittests/Driver/ToolChainTest.cpp --- ToolChain tests -------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //