Arch Linux

Description:
When editing C++ code, the IDE will occasionally crash.

Additional info:
* package version: 7.0.2-1
* upstream bug report: https://bugreports.qt.io/browse/QTCREATORBUG-27096
* upstream fix merged into 7.0 branch: https://codereview.qt-project.org/c/qt-creator/qt-creator/+/412842

Steps to reproduce:
1. Edit sufficiently complicated C++ code, generally when templates are involved.
2. In many cases semantic highlighting will briefly stop showing or code completion will stop working. This is due to clangd crashing in the background, and may also cause the IDE to crash.

The cause of this crash is clangd crashing in the background and the IDE not always taking this into account when trying to handle the results when showing function hints. The fix (https://codereview.qt-project.org/c/qt-creator/qt-creator/+/412842) adds more checks to ensure that the internal objects managing the clangd process are still valid.

In my experience with editing a complex C++ project, I might get 10-20 clangd crashes and 1-3 Qt Creator crashes in a day. After applying this patch, I've had dozens of clangd crashes without Qt Creator itself crashing as a result.