wayland: Look up pressed keys via keycodes instead of scancodes on keyboard entry

On window focus, look up the pressed modifier keys via keycodes instead of scancodes to handle the case of remapped keys, as xkb remapping changes the associated keycode, not the scancode.

src/video/wayland/SDL_waylandevents.c

@@ -1160,21 +1160,6 @@ static void keyboard_handle_enter(void *data, struct wl_keyboard *keyboard,
                                   uint32_t serial, struct wl_surface *surface,
                                   struct wl_array *keys)
 {
-    /* Caps Lock not included because it only makes sense to consider modifiers
-     * that get held down, for the case where a user clicks on an unfocused
-     * window with a modifier key like Shift pressed, in a situation where the
-     * application handles Shift+click differently from a click
-     */
-    const SDL_Scancode mod_scancodes[] = {
-        SDL_SCANCODE_LSHIFT,
-        SDL_SCANCODE_RSHIFT,
-        SDL_SCANCODE_LCTRL,
-        SDL_SCANCODE_RCTRL,
-        SDL_SCANCODE_LALT,
-        SDL_SCANCODE_RALT,
-        SDL_SCANCODE_LGUI,
-        SDL_SCANCODE_RGUI,
-    };
     struct SDL_WaylandInput *input = data;
     SDL_WindowData *window;
     uint32_t *key;
@@ -1203,14 +1188,21 @@ static void keyboard_handle_enter(void *data, struct wl_keyboard *keyboard,
 
     wl_array_for_each (key, keys) {
         const SDL_Scancode scancode = Wayland_get_scancode_from_key(input, *key + 8);
-
-        if (scancode != SDL_SCANCODE_UNKNOWN) {
-            for (uint32_t i = 0; i < sizeof mod_scancodes / sizeof *mod_scancodes; ++i) {
-                if (mod_scancodes[i] == scancode) {
-                    SDL_SendKeyboardKey(0, SDL_PRESSED, scancode);
-                    break;
-                }
-            }
+        const SDL_KeyCode keycode = SDL_GetKeyFromScancode(scancode);
+
+        switch (keycode) {
+        case SDLK_LSHIFT:
+        case SDLK_RSHIFT:
+        case SDLK_LCTRL:
+        case SDLK_RCTRL:
+        case SDLK_LALT:
+        case SDLK_RALT:
+        case SDLK_LGUI:
+        case SDLK_RGUI:
+            SDL_SendKeyboardKey(0, SDL_PRESSED, scancode);
+            break;
+        default:
+            break;
         }
     }
 }