[libsoup] build: Add more common-sense error cflags

[Patrick Griffis <pgriffis src gnome org>]

commit cfb9193039e2fb54e13e84bd3378b649c0f9afba
Author: Patrick Griffis <pgriffis igalia com>
Date:   Sun Mar 21 14:55:00 2021 -0500

    build: Add more common-sense error cflags

 meson.build | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/meson.build b/meson.build
index 8ab7c6df..31430cd1 100644
--- a/meson.build
+++ b/meson.build
@@ -63,6 +63,8 @@ else
       '-Werror=implicit-function-declaration',
       '-Werror=aggregate-return',
       '-Werror=format=2',
+      '-Werror=return-type',
+      '-Werror=incompatible-pointer-types',
       '-Wstrict-prototypes',
       '-Wno-format-zero-length',
       '-Wno-missing-include-dirs',