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/llvm/lib/Option/Arg.cpp b/llvm/lib/Option/Arg.cpp
index 4ce40e3..420279b 100644
--- a/llvm/lib/Option/Arg.cpp
+++ b/llvm/lib/Option/Arg.cpp
@@ -1,9 +1,8 @@
 //===- Arg.cpp - Argument Implementations ---------------------------------===//
 //
-//                     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/llvm/lib/Option/ArgList.cpp b/llvm/lib/Option/ArgList.cpp
index 8a7d59d..36e2f45 100644
--- a/llvm/lib/Option/ArgList.cpp
+++ b/llvm/lib/Option/ArgList.cpp
@@ -1,9 +1,8 @@
 //===- ArgList.cpp - Argument List Management -----------------------------===//
 //
-//                     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/llvm/lib/Option/LLVMBuild.txt b/llvm/lib/Option/LLVMBuild.txt
index 0b78cf2..3443492 100644
--- a/llvm/lib/Option/LLVMBuild.txt
+++ b/llvm/lib/Option/LLVMBuild.txt
@@ -1,9 +1,8 @@
 ;===- ./lib/Option/LLVMBuild.txt -------------------------------*- Conf -*--===;
 ;
-;                     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/llvm/lib/Option/OptTable.cpp b/llvm/lib/Option/OptTable.cpp
index 312ff78..c0a1861 100644
--- a/llvm/lib/Option/OptTable.cpp
+++ b/llvm/lib/Option/OptTable.cpp
@@ -1,9 +1,8 @@
 //===- OptTable.cpp - Option Table Implementation -------------------------===//
 //
-//                     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/llvm/lib/Option/Option.cpp b/llvm/lib/Option/Option.cpp
index f9d8a5e..1e3b545 100644
--- a/llvm/lib/Option/Option.cpp
+++ b/llvm/lib/Option/Option.cpp
@@ -1,9 +1,8 @@
 //===- Option.cpp - Abstract Driver Options -------------------------------===//
 //
-//                     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
 //
 //===----------------------------------------------------------------------===//