Add changes file for Qt 5.12.5 and fix 5.12.4 change file

+ 3394807b Bump version
+ 0fc7e18b Core/IO/Bluetooth - fix ambiguous conversions
+ 8a6d9c30 Fix compilation with C++20
+ 4ac755bb winrt: Do not try to delete nullptr worker
+ 263fc518 Do not handle PAIRING_VARIANT_PIN
+ 8110fdd4 Core/IO/Bluetooth - fix ambiguous conversions for macOS
+ c9d585da winrt: Add limitations to bluetooth overview page
+ 406b18fd

 Fix QLEAdvertisingData::setManufacturerData on Android

Change-Id: Ib8bf9529e85e8f8c2f76c203120afb3d9ceca492
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

dist/changes-5.12.4

@@ -18,7 +18,7 @@ Each of these identifiers can be entered in the bug tracker to obtain more
 information about a particular change.
 
 ****************************************************************************
-*                              Qt 5.12.3 Changes                           *
+*                              Qt 5.12.4 Changes                           *
 ****************************************************************************
 
 QtBluetooth

dist/changes-5.12.5

+Qt 5.12.5 is a bug-fix release. It maintains both forward and backward
+compatibility (source and binary) with Qt 5.12.0 through 5.12.4.
+
+For more details, refer to the online documentation included in this
+distribution. The documentation is also available online:
+
+https://doc.qt.io/qt-5/index.html
+
+The Qt version 5.12 series is binary compatible with the 5.11.x series.
+Applications compiled for 5.11 will continue to run with 5.12.
+
+Some of the changes listed in this file include issue tracking numbers
+corresponding to tasks in the Qt Bug Tracker:
+
+https://bugreports.qt.io/
+
+Each of these identifiers can be entered in the bug tracker to obtain more
+information about a particular change.
+
+****************************************************************************
+*                              Qt 5.12.5 Changes                           *
+****************************************************************************
+
+QtBluetooth
+-----------
+
+ - [QTBUG-76847] Fixed ambiguous type conversions on Apple platforms.
+
+ - [QTBUG-75089] Removed attempt to delete nullptr on WinRT when calling
+   QBluetoothDeviceDiscoveryAgent::stop().
+
+ - [QTBUG-76565] Reverted handling of PAIRING_VARIANT_PIN by
+   QBluetoothLocalDevice on Android.
+
+ - [QTBUG-62520] Improved documentation covering platform limitations on WinRT.
+
+ - Fixed QLowEnergyAdvertisingData::setManufacturerData() on Android. Previously a wrong
+   JNI signature prevented setting the data.