tests: Move Wayland protocols to dedicated directory

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2810>

src/tests/meson.build

@@ -123,6 +123,7 @@ if have_clutter_tests
   subdir('clutter')
 endif
 
+subdir('protocol')
 subdir('wayland-test-clients')
 
 if have_installed_tests

src/tests/protocol/meson.build

@@ -0,0 +1,32 @@
+test_driver_server_header = custom_target(
+  'test-driver server header',
+  input: 'test-driver.xml',
+  output: 'test-driver-server-protocol.h',
+  command: [
+    wayland_scanner,
+    'server-header',
+    '@INPUT@', '@OUTPUT@',
+  ]
+)
+
+test_driver_client_header = custom_target(
+  'test-driver client header',
+  input: 'test-driver.xml',
+  output: 'test-driver-client-protocol.h',
+  command: [
+    wayland_scanner,
+    'client-header',
+    '@INPUT@', '@OUTPUT@',
+  ]
+)
+
+test_driver_protocol_code = custom_target(
+  'test-driver source',
+  input: 'test-driver.xml',
+  output: 'test-driver-protocol.c',
+  command: [
+    wayland_scanner,
+    'private-code',
+    '@INPUT@', '@OUTPUT@',
+  ]
+)

src/tests/wayland-test-clients/meson.build

@@ -3,38 +3,6 @@ wayland_test_client_installed_tests_libexecdir = join_paths(
   'wayland-test-clients',
 )
 
-test_driver_server_header = custom_target(
-  'test-driver server header',
-  input: 'test-driver.xml',
-  output: 'test-driver-server-protocol.h',
-  command: [
-    wayland_scanner,
-    'server-header',
-    '@INPUT@', '@OUTPUT@',
-  ]
-)
-
-test_driver_client_header = custom_target(
-  'test-driver client header',
-  input: 'test-driver.xml',
-  output: 'test-driver-client-protocol.h',
-  command: [
-    wayland_scanner,
-    'client-header',
-    '@INPUT@', '@OUTPUT@',
-  ]
-)
-
-test_driver_protocol_code = custom_target(
-  'test-driver source',
-  input: 'test-driver.xml',
-  output: 'test-driver-protocol.c',
-  command: [
-    wayland_scanner,
-    'private-code',
-    '@INPUT@', '@OUTPUT@',
-  ]
-)
 
 common_sources = [
   'wayland-test-client-utils.c',