port https://github.com/mapbox/mapbox-gl-js/pull/4781
This improves legibility of labels that follow lines in pitched views.
The previous approach used the limited information in the shader to
calculate put the glyph in approximatelyright place. The new approach
does this more accurately by doing it on the cpu where we have access to
the entire line geometry.
Viewport-aligned curved labels start to look very strange in the distance. Until we have a better system for projecting them, just prevent them from showing.
```
==24942== Conditional jump or move depends on uninitialised value(s)
==24942== at 0x7D943D: mbgl::RenderGeoJSONSource::update(mbgl::Immutable<mbgl::style::Source::Impl>, std::vector<mbgl::Immutable<mbgl::style::Layer::Impl>, std::allocator<mbgl::Immutable<mbgl::style::Layer::Impl> > > const&, bool, bool, mbgl::TileParameters const&) (in /home/tmpsantos/Projects/mapbox-gl-native/build/linux-x86_64/Release/mbgl-test)
==24942== by 0x796445: mbgl::RenderStyle::update(mbgl::UpdateParameters const&) (in /home/tmpsantos/Projects/mapbox-gl-native/build/linux-x86_64/Release/mbgl-test)
==24942== by 0x77E29D: mbgl::Map::Impl::render(mbgl::View&) (in /home/tmpsantos/Projects/mapbox-gl-native/build/linux-x86_64/Release/mbgl-test)
==24942== by 0x77E559: mbgl::Map::Impl::renderStill() (in /home/tmpsantos/Projects/mapbox-gl-native/build/linux-x86_64/Release/mbgl-test)
==24942== by 0xA39772: uv__async_event (async.c:98)
==24942== by 0xA398F8: uv__async_io (async.c:138)
==24942== by 0xA4375F: uv__io_poll (linux-core.c:380)
==24942== by 0xA3A1F2: uv_run (core.c:354)
==24942== by 0x61BADC: API_ZoomHistory_Test::TestBody() (in /home/tmpsantos/Projects/mapbox-gl-native/build/linux-x86_64/Release/mbgl-test)
==24942== by 0x89FDE9: void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) (in /home/tmpsantos/Projects/mapbox-gl-native/build/linux-x86_64/Release/mbgl-test)
==24942== by 0x885450: testing::Test::Run() (in /home/tmpsantos/Projects/mapbox-gl-native/build/linux-x86_64/Release/mbgl-test)
==24942== by 0x88642F: testing::TestInfo::Run() (in /home/tmpsantos/Projects/mapbox-gl-native/build/linux-x86_64/Release/mbgl-test)
==24942==
```
Introducing two new attributes to enable property functions for line-width (#9250) pushed the attribute count over GL_MAX_VERTEX_ATTRIBS on some devices. Now we selectively bind only attributes that are used, making it unlikely to surpass GL_MAX_VERTEX_ATTRIBS.
We're storing GeometryTileFeature objects in SymbolLayout, but they may reference data in GeometryTileLayer, which could go away if we don't retain it.
