Fix handling of keys with Ctrl modifier in wxSTC under OS X

The real Ctrl key is represented by "meta" modifier bit under OS X as the
"ctrl" bit is used for the Cmd key, but the previously used KeyDown() method
didn't support the meta bit at all, so key combinations using Ctrl didn't
work.

Also remove obsolete code which mapped "meta" to "ctrl", probably predating
the mapping of Cmd to "ctrl" at wx API level.

See #16243.

src/stc/ScintillaWX.cpp

@@ -1037,11 +1037,7 @@ int  ScintillaWX::DoKeyDown(const wxKeyEvent& evt, bool* consumed)
         return 0;
     }
 
-    bool shift = evt.ShiftDown(),
-         ctrl  = evt.ControlDown(),
-         alt   = evt.AltDown();
-
-    if (ctrl && key >= 1 && key <= 26 && key != WXK_BACK)
+    if (evt.RawControlDown() && key >= 1 && key <= 26 && key != WXK_BACK)
         key += 'A' - 1;
 
     switch (key) {
@@ -1082,23 +1078,18 @@ int  ScintillaWX::DoKeyDown(const wxKeyEvent& evt, bool* consumed)
     case WXK_MENU:              key = SCK_MENU; break;
     }
 
-#ifdef __WXMAC__
-    if ( evt.MetaDown() ) {
-        // check for a few common Mac Meta-key combos and remap them to Ctrl
-        // for Scintilla
-        switch ( key ) {
-        case 'Z':       // Undo
-        case 'X':       // Cut
-        case 'C':       // Copy
-        case 'V':       // Paste
-        case 'A':       // Select All
-            ctrl = true;
-            break;
-        }
-    }
-#endif
-
-    int rv = KeyDown(key, shift, ctrl, alt, consumed);
+    int rv = KeyDownWithModifiers
+             (
+                key,
+                ModifierFlags
+                (
+                    evt.ShiftDown(),
+                    evt.ControlDown(),
+                    evt.AltDown(),
+                    evt.RawControlDown()
+                ),
+                consumed
+             );
 
     if (key)
         return rv;