Default to release builds in Meson

Also define NDEBUG for release builds.

Author: saghul

meson.build

@@ -5,6 +5,8 @@ project(
   default_options: [
     'c_std=gnu11,c11',
     'warning_level=3',
+    'buildtype=release',
+    'b_ndebug=if-release',
   ],
   license: 'MIT',
   license_files: 'LICENSE',