Add changes file for Qt 5.15.1

+ 5488f07 Fix Clang 10 warning about inconsistent override
+ 267fba6 Bump version

Change-Id: Ic59946675ff991117af83c27ed726e195c721cfc
Reviewed-by: Jani Heikkinen <[email protected]>
(cherry picked from commit 835b594)
Reviewed-by: Qt Cherry-pick Bot <[email protected]>

Author: Antti Kokko

dist/changes-5.15.1

@@ -0,0 +1,20 @@
+Qt 5.15.1 is a bug-fix release. It maintains both forward and backward
+compatibility (source and binary) with Qt 5.15.0.
+
+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 5.15 series is binary compatible with the 5.14.x series.
+Applications compiled for 5.14 will continue to run with 5.15.
+
+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.
+
+ - This release contains only minor code improvements.