This was a good test for my cross toolchain with gcc 6.3.0 I uploaded some days ago: the new Qt 5.10.0 built with -march=armv8-a -mtune=cortex-a53 -mfpu=crypto-neon-fp-armv8 -mfloat-abi=hard, including POT for video acceleration on Raspbian Stretch. The build includes most Qt modules plus Qt WebKit (the modernized QtWebKit from
Konstantin Tokarev, version 5.212, https://github.com/annulen/webkit) plus QtWebEngine 5.9.1, a bit patched to build here. I didn't test browsers much, you'll have to work on those yourself if you need them.
By using the Qt build and the cross toolchain you can build your own applications.
Download here the build for Qt 5.10.0 with POT 5.7.
Download here the cross toolchain.