Cherry-pick the whole https://github.com/mono/mono/pull/16636
We were also attempting to patch the wrong folder previously (I had it
working in my local tests but committed the wrong patch when rebasing
to make the Git history pretty... :)).
To get WebAssembly templates to actually work, we need to use
Mono 6.6 (currently in preview), which doesn't have tags yet
but is in the `2019-08` branch. So I dehardcoded the `mono-`
prefix for the git tree-ish to allow using `./build.sh 2019-08`.
6.6 doesn't build with msbuild 16.0, so I'm upgrading to its
matching version 16.3. There are no DEB files for 16.3 on the
EOL'ed Ubuntu 14.04, but it seems that the 16.04 packages install
cleanly.
We also backport a patch from mono's master branch to fix wasm
support further, and enable parallel build jobs for make.
We force using Emscripten 1.38.47 as there is a regression in 1.38.48
and 1.39.x which makes the generation of our .wasm file fail.
Up until now we used the desktop BCL (compiled with desktop Mono)
for both desktop and Android, but that does not work for WebAssembly
(and we suspect Android issues related to it).
So we now build the Android and WebAssembly BCLs in the relevant
containers, which are later copied in the templates directory to
include on export. We already have the desktop BCL from the regular
build.
Adds support for building Mono templates for Android in 3.2/master.
We use the script from https://github.com/godotengine/godot-mono-builds
to build Mono for all arches with the right options, and a patch included
from https://github.com/godotengine/godot/blob/master/modules/mono/build_scripts/patches/fix-mono-android-tkill.diff
which is also necessary.
I also moved the SDK to a `sdk` folder to make the `$HOME` more tidy,
especially since the Mono build scripts install the mono toolchains in
`$HOME` too by default.
Using a git clone for specific mono version tag, as the upstream tarballs
are iffy (the 5.18.1.3 tarball lacks files needed to build on Android).
* Mono config on MacOSX is not portable from the Linux and Windows
version.
* Rename the compilers so that 'gcc' and 'g++' are the new version by
default.
* Add default environment variables to containers.
