chore: make yuzu REUSE compliant

[REUSE] is a specification that aims at making file copyright
information consistent, so that it can be both human and machine
readable. It basically requires that all files have a header containing
copyright and licensing information. When this isn't possible, like
when dealing with binary assets, generated files or embedded third-party
dependencies, it is permitted to insert copyright information in the
`.reuse/dep5` file.

Oh, and it also requires that all the licenses used in the project are
present in the `LICENSES` folder, that's why the diff is so huge.
This can be done automatically with `reuse download --all`.

The `reuse` tool also contains a handy subcommand that analyzes the
project and tells whether or not the project is (still) compliant,
`reuse lint`.

Following REUSE has a few advantages over the current approach:

- Copyright information is easy to access for users / downstream
- Files like `dist/license.md` do not need to exist anymore, as
  `.reuse/dep5` is used instead
- `reuse lint` makes it easy to ensure that copyright information of
  files like binary assets / images is always accurate and up to date

To add copyright information of files that didn't have it I looked up
who committed what and when, for each file. As yuzu contributors do not
have to sign a CLA or similar I couldn't assume that copyright ownership
was of the "yuzu Emulator Project", so I used the name and/or email of
the commit author instead.

[REUSE]: https://reuse.software

Follow-up to 01cf05bc75b1e47beb08937439f3ed9339e7b254

5 files changed, 15 insertions, 0 deletions

diff --git a/src/video_core/host_shaders/CMakeLists.txt b/src/video_core/host_shaders/CMakeLists.txt
index 190fc6aea..2149ab93e 100644
--- a/src/video_core/host_shaders/CMakeLists.txt
+++ b/src/video_core/host_shaders/CMakeLists.txt
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2018 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 set(FIDELITYFX_INCLUDE_DIR ${CMAKE_SOURCE_DIR}/externals/FidelityFX-FSR/ffx-fsr)
 
 set(GLSL_INCLUDES
diff --git a/src/video_core/host_shaders/StringShaderHeader.cmake b/src/video_core/host_shaders/StringShaderHeader.cmake
index 1b4bc6103..9f7525535 100644
--- a/src/video_core/host_shaders/StringShaderHeader.cmake
+++ b/src/video_core/host_shaders/StringShaderHeader.cmake
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2020 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 set(SOURCE_FILE ${CMAKE_ARGV3})
 set(HEADER_FILE ${CMAKE_ARGV4})
 set(INPUT_FILE ${CMAKE_ARGV5})
diff --git a/src/video_core/host_shaders/source_shader.h.in b/src/video_core/host_shaders/source_shader.h.in
index 929dec39b..f189ee06b 100644
--- a/src/video_core/host_shaders/source_shader.h.in
+++ b/src/video_core/host_shaders/source_shader.h.in
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: 2020 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
 #pragma once
 
 #include <string_view>
diff --git a/src/video_core/host_shaders/vulkan_present_scaleforce_fp16.frag b/src/video_core/host_shaders/vulkan_present_scaleforce_fp16.frag
index 924c03060..3dc9c0df5 100644
--- a/src/video_core/host_shaders/vulkan_present_scaleforce_fp16.frag
+++ b/src/video_core/host_shaders/vulkan_present_scaleforce_fp16.frag
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: 2021 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
 #version 460
 
 #extension GL_GOOGLE_include_directive : enable
diff --git a/src/video_core/host_shaders/vulkan_present_scaleforce_fp32.frag b/src/video_core/host_shaders/vulkan_present_scaleforce_fp32.frag
index a594b83ca..77ed07552 100644
--- a/src/video_core/host_shaders/vulkan_present_scaleforce_fp32.frag
+++ b/src/video_core/host_shaders/vulkan_present_scaleforce_fp32.frag
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: 2021 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
 #version 460
 
 #extension GL_GOOGLE_include_directive : enable