[CI] Build std_spec in batches on 32-bit

[straight-shoota]

Resolves #11073

This should make 32-bit specs run again.

The stdlib specs were previously built as a single binary and executed in batches (on 32-bit linux). This patch completely separates the build process in order to reduce memory demand at compile time. It also appears to run faster. So we might consider using this approach for all architectures.

The CI job still only runs stdlib specs against the latest release compiler, without building a new compiler from the development branch.

[straight-shoota]

This now hits a different error in the second batch:

  Invalid memory access (signal 11) at address 0x0
  [0x8aeea53] ???
  [0x8aeea0e] ???
  [0x9ca8929] ???

This is different from the original error, which seems to be originating from LLVM running out of memory. Perhaps it's just different depending on when it runs out of memory.

But the thing is: this really shouldn't run out of memory anymore. When I built it locally, it showed about 800MB of memory use. That should be totally fine.
So this might be something entirely different.

I tried to recreate with the same docker image locally, and the same error appears. But as soon as I run the command in the container interactively instead of passing it directly to the container's shell via -s, the spec builds and runs correctly. This feels really odd, but appears to be very consistent.

[beta-ziliani]

just to be on the safe side, are you certain that the LLVM version is < 11?

[straight-shoota]

Yeah, I was wondering about that, but no, it's LLVM 10:

Crystal 1.1.1 [6d9a1d583] (2021-07-26)

LLVM: 10.0.1
Default target: i386-unknown-linux-gnu

[sdogruyol]

Thank you @straight-shoota 🙏