[vala/0.36] codegen: Add prototype for *_register_type() function

[Rico Tzschichholz <ricotz src gnome org>]

commit 0f2b09a6637151d1c27375a82153755070f4e08e
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Sun Nov 4 20:22:22 2018 +0100

    codegen: Add prototype for *_register_type() function
    
    Found with -Werror=missing-prototypes

 codegen/valatyperegisterfunction.vala | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/codegen/valatyperegisterfunction.vala b/codegen/valatyperegisterfunction.vala
index dbfe923f6..9386e99c6 100644
--- a/codegen/valatyperegisterfunction.vala
+++ b/codegen/valatyperegisterfunction.vala
@@ -86,6 +86,10 @@ public abstract class Vala.TypeRegisterFunction {
                        fun = new CCodeFunction ("%s_register_type".printf 
(CCodeBaseModule.get_ccode_lower_case_name (get_type_declaration ())), "GType");
                        fun.add_parameter (new CCodeParameter ("module", "GTypeModule *"));
 
+                       fun.is_declaration = true;
+                       declaration_fragment.append (fun.copy ());
+                       fun.is_declaration = false;
+
                        var get_fun = new CCodeFunction ("%s_get_type".printf 
(CCodeBaseModule.get_ccode_lower_case_name (get_type_declaration ())), "GType");
                        get_fun.modifiers = CCodeModifiers.CONST;