CI (buildkite): ensure passing --output-sync when passing -j

[vtjnash]

To be at feature-parity with old buildbots (assuming the buildkite workers aren't ancient dinosaurs like some of the buildbots).

[DilumAluthge]

Could you explain what this does?

[DilumAluthge]

(assuming the buildkite workers aren't ancient dinosaurs like some of the buildbots)

Just FYI, right now we are only running Buildkite agents on the newer AMDCI machines, but eventually, as we transition everything from Buildbot to Buildkite, we may end up running some Buildkite agents on some of the older machines as well.

[DilumAluthge]

(assuming the buildkite workers aren't ancient dinosaurs like some of the buildbots)

Just FYI, right now we are only running Buildkite agents on the newer AMDCI machines, but eventually, as we transition everything from Buildbot to Buildkite, we may end up running some Buildkite agents on some of the older machines as well.

But if your concern (about old machines) is only about having too old a version of make, we can make sure that our build environments have a recent enough version of make.

[staticfloat]

Yes, our grand plan is to not have ancient tool versions anymore, just ancient glibc versions.

[DilumAluthge]

We need to update the coverage pipeline signature before merging this PR.

[DilumAluthge]

I updated the signature.

[vtjnash]

Looks like a I missed the ASAN builder, but I don't see where it called make -j

Separately, the linux32 trampolines seem to have an error in them (according to the linker) @staticfloat