move igBeginPopupModal implementations from ImGuiNative to ImGui

src/ImGui.NET/ImGui.cs

@@ -884,22 +884,26 @@ namespace ImGuiNET
 
         public static bool BeginPopupModal(string name)
         {
-            return ImGuiNative.igBeginPopupModal(name, WindowFlags.Default);
+            return BeginPopupModal(name, WindowFlags.Default);
         }
 
-        public static bool BeginPopupModal(string name, WindowFlags extraFlags)
+        public static bool BeginPopupModal(string name, ref bool opened)
         {
-            return ImGuiNative.igBeginPopupModal(name, extraFlags);
+            return BeginPopupModal(name, ref opened, WindowFlags.Default);
         }
 
-        public static bool BeginPopupModal(string name, ref bool opened)
+        public static unsafe bool BeginPopupModal(string name, WindowFlags extra_flags)
         {
-            return ImGuiNative.igBeginPopupModal(name, ref opened, WindowFlags.Default);
+            return ImGuiNative.igBeginPopupModal(name, null, extra_flags);
         }
 
-        public static bool BeginPopupModal(string name, ref bool opened, WindowFlags extraFlags)
+        public static unsafe bool BeginPopupModal(string name, ref bool p_opened, WindowFlags extra_flags)
         {
-            return ImGuiNative.igBeginPopupModal(name, ref opened, extraFlags);
+            byte value = p_opened ? (byte)1 : (byte)0;
+            bool result = ImGuiNative.igBeginPopupModal(name, &value, extra_flags);
+
+            p_opened = value == 1 ? true : false;
+            return result;
         }
 
         public static bool Selectable(string label, bool isSelected, SelectableFlags flags)

src/ImGui.NET/ImGuiNative.cs

@@ -584,20 +584,6 @@ namespace ImGuiNET
         [return: MarshalAs(UnmanagedType.I1)]
         public static extern bool igBeginPopupModal(string name, byte* p_opened, WindowFlags extra_flags);
 
-        public static bool igBeginPopupModal(string name, WindowFlags extra_flags)
-        {
-            return igBeginPopupModal(name, null, extra_flags);
-        }
-
-        public static bool igBeginPopupModal(string name, ref bool p_opened, WindowFlags extra_flags)
-        {
-            byte value = p_opened ? (byte)1 : (byte)0;
-            bool result = igBeginPopupModal(name, &value, extra_flags);
-
-            p_opened = value == 1 ? true : false;
-            return result;
-        }
-
         [DllImport(cimguiLib)]
         [return: MarshalAs(UnmanagedType.I1)]
         public static extern bool igBeginPopupContextItem(string str_id, int mouse_button);