Use the one without assertions for cross-building toolchains, as the
one with assertions is too slow. In practice, one or more of the cross
toolchain builds end up timing out (exceeding the 6 h limit) almost
every day in the scheduled builds, requiring reruns (sometimes
multiple reruns) to complete successfully in time.
(There seems to be a big variation in what actual runner the jobs
end up using; some runners complete the cross builds in around 4 h,
while some are much slower, and seem to require 5-6 hours or more.)
In practice, during the 2 months that I've had scheduled jobs
running on Github Actions, there haven't been any failed asserts
triggered and caught in the cross builds (but once in the cross builds
of ffmpeg, which still keep using a toolchain with asserts enabled).
Latest git llvm-project has switched to requiring C++17, while
lldb-mi still is built in C++14 mode. This makes the scheduled builds
fail. Therefore, disable building lldb-mi for now in the scheduled
builds, until this has been fixed in the latest git main versions
of lldb-mi.
Zstd is available and gets autodetected, but it's only available in
native form, not in arm64 form.
Also, for the existing workaround, instead of entirely disabling lldb,
one could pass -DLLDB_ENABLE_PYTHON=OFF instead.
Test building the toolchain on all supported platforms for building
it (linux, macOS, msys2). Produce cross-built standalone toolchains
that run on Windows for all 4 supported architectures.
Run scheduled builds (daily), built with the latest git versions of
most components. For scheduled builds, the linux toolchain is built
with assertions enabled, as latest git version of llvm occasionally
can have regressions, and many such are caught by having assertions
enabled and building enough code that exercise many code generation
cases.