[gobject-introspection/warn-flags] build: enable -Wincompatible-pointer-types

[Christoph Reiter <creiter src gnome org>]

commit 69615e9401038ec46a75c94fec9e6bc6d38f3e90
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Sun Jul 29 14:47:58 2018 +0200

    build: enable -Wincompatible-pointer-types

 configure.ac               | 2 +-
 girepository/gitypelib.c   | 2 +-
 tests/scanner/annotation.c | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index b2283282..6898741a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -67,7 +67,7 @@ AX_APPEND_COMPILE_FLAGS([-Wno-switch-enum])
 # FIXME: Fix the warnings and remove the flags
 AX_APPEND_COMPILE_FLAGS([-Wno-redundant-decls -Wno-switch-default -Wno-shadow -Wno-deprecated-declarations 
-Wno-cast-function-type -Wno-type-limits])
 AX_APPEND_COMPILE_FLAGS([-Wno-duplicated-branches -Wno-implicit-fallthrough -Wno-suggest-attribute=format 
-Wno-double-promotion -Wno-sign-compare])
-AX_APPEND_COMPILE_FLAGS([-Wno-old-style-definition -Wno-strict-prototypes -Wno-incompatible-pointer-types])
+AX_APPEND_COMPILE_FLAGS([-Wno-old-style-definition -Wno-strict-prototypes])
 
 WARN_CFLAGS_PYTHON="$WARN_CFLAGS"
 AX_APPEND_COMPILE_FLAGS([-Wno-discarded-qualifiers], [WARN_CFLAGS_PYTHON])
diff --git a/girepository/gitypelib.c b/girepository/gitypelib.c
index 8ad13604..f2b20607 100644
--- a/girepository/gitypelib.c
+++ b/girepository/gitypelib.c
@@ -324,7 +324,7 @@ g_typelib_matches_gtype_name_prefix (GITypelib *typelib,
 {
   Header *header = (Header *)typelib->data;
   const char *c_prefix;
-  gchar *prefix;
+  const gchar *prefix;
   gboolean ret = FALSE;
   StrSplitIter split_iter;
   gsize gtype_name_len;
diff --git a/tests/scanner/annotation.c b/tests/scanner/annotation.c
index 0f3858f2..fb8b48f4 100644
--- a/tests/scanner/annotation.c
+++ b/tests/scanner/annotation.c
@@ -400,7 +400,7 @@ regress_annotation_object_get_objects (RegressAnnotationObject *object)
 GObject*
 regress_annotation_object_create_object (RegressAnnotationObject *object)
 {
-  return g_object_ref (object);
+  return G_OBJECT (g_object_ref (object));
 }
 
 /**