File cxxflags.patch of Package libqt5-qtwebengine

Index: qtwebengine-everywhere-src-5.15.17/src/core/core_common.pri
===================================================================
--- qtwebengine-everywhere-src-5.15.17.orig/src/core/core_common.pri
+++ qtwebengine-everywhere-src-5.15.17/src/core/core_common.pri
@@ -15,6 +15,6 @@ qtConfig(webengine-webchannel): QT += we
 # LTO does not work for Chromium at the moment, so disable it completely for core.
 CONFIG -= ltcg
 
-# Chromium requires C++14
-CONFIG += c++14
+# Chromium requires C++17
+CONFIG += c++17