meson, data: create/install gimp-release file with meson too.

data/meson.build

@@ -14,3 +14,13 @@ subdir('tool-presets')
 meson.add_install_script('sh', '-c',
   'mkdir -p $MESON_INSTALL_DESTDIR_PREFIX/@0@'.format(gimpdatadir / 'fonts')
 )
+
+custom_target('gimp-release',
+  output: [ 'gimp-release' ],
+  command: [
+    'echo', ['[package]' + '\nrevision=@0@'.format(get_option('revision'))]
+  ],
+  capture: true,
+  install: true,
+  install_dir: gimpdatadir,
+)

meson.build

@@ -1101,7 +1101,6 @@ conf.set_quoted('BUG_REPORT_URL', bug_report_url)
 # Build identifiers #
 
 conf.set_quoted('GIMP_BUILD_ID', get_option('build-id'))
-conf.set('GIMP_BUILD_REVISION', get_option('revision'))
 conf.set_quoted('GIMP_BUILD_PLATFORM', host_os)
 if platform_linux
   conf.set_quoted('GIMP_BUILD_PLATFORM_FAMILY', 'linux')

meson_options.txt

@@ -13,7 +13,7 @@ option('shmem-type',        type: 'combo',   value: 'auto', description: 'Shared
                                              choices: [ 'none', 'sysv', 'posix', 'win32', 'auto' ])
 
 option('build-id',          type: 'string',  value: 'unknown', description: 'Unique string used to define your build')
-option('revision',          type: 'integer', value: 0,    description: 'Revision increment for a same build/version/platform')
+option('revision',          type: 'integer', value: 0,    description: 'Revision increment for a package')
 option('check-update',      type: 'boolean', value: true, description: 'GIMP will look up new version availability on startup')
 
 option('bug-report-url',    type: 'string',  value: '',   description: 'URL used by the debug dialog to report bugs')