build: Explicitly disable -Wmissing-field-initializers

This is on by default at -Werror level in the macOS CI build, causing
the build to fail. We do not consider missing field initializers to be a
bug: an initializer that does not mention all fields has a well-defined
meaning (remaining fields are initialized as if via .field = 0).

Resolves: https://gitlab.gnome.org/GNOME/glib/-/issues/2812
Signed-off-by: Simon McVittie <smcv@collabora.com>
diff --git a/meson.build b/meson.build
index 0edea24..3151d7e 100644
--- a/meson.build
+++ b/meson.build
@@ -495,6 +495,8 @@
     '-Werror=missing-include-dirs',
     '-Werror=pointer-arith',
     '-Werror=unused-result',
+    # Missing field initializers have a well-defined meaning
+    '-Wno-missing-field-initializers',
   ]
 
   warning_c_args = warning_common_args + [