Build: Add option to disable building tests

meson_options.txt

@@ -14,3 +14,8 @@ option('build_tools',
     type: 'boolean',
     value: true,
     description: 'Build dav1d cli tools')
+
+option('build_tests',
+    type: 'boolean',
+    value: true,
+    description: 'Build dav1d tests')

tests/meson.build

+#
+# Build definition for the dav1d tests
+#
+
+# Leave subdir if tests are disabled
+if not get_option('build_tests')
+    subdir_done()
+endif
+
 if is_asm_enabled
     checkasm_sources = files('checkasm/checkasm.c')