Annotate *.inc c++ files so they are recognized as such.

Since *.inc is not a common filename suffix, editors and
other tools might not recognize these as c++ and would
not offer language speficific features such as
syntax-highlighting.

This uses the commonly used -*- c++ -*- annotation recongized
by many tools.

PiperOrigin-RevId: 506953120

src/google/protobuf/compiler/cpp/unittest.inc

@@ -1,3 +1,4 @@
+// -*- c++ -*-
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/

src/google/protobuf/map_test.inc

@@ -1,3 +1,4 @@
+// -*- c++ -*-
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/

src/google/protobuf/map_test_util.inc

@@ -1,3 +1,4 @@
+// -*- c++ -*-
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/

src/google/protobuf/message_unittest.inc

@@ -1,3 +1,4 @@
+// -*- c++ -*-
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/

src/google/protobuf/port_def.inc

@@ -1,3 +1,4 @@
+// -*- c++ -*-
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/

src/google/protobuf/port_undef.inc

@@ -1,3 +1,4 @@
+// -*- c++ -*-
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/

src/google/protobuf/proto3_lite_unittest.inc

@@ -1,3 +1,4 @@
+// -*- c++ -*-
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/

src/google/protobuf/test_util.inc

@@ -1,3 +1,4 @@
+// -*- c++ -*-
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/

src/google/protobuf/wire_format_unittest.inc

@@ -1,3 +1,4 @@
+// -*- c++ -*-
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/