runtime: docker: add armhf and armel container targets

[roxell]

Add armhf and armel as new targets alongside arm and armv5. This builds containers with the new names first.

armhf matches arm (hard-float).
armel matches armv5 (soft-float).

For korg-gcc only armel is added since the korg toolchain uses the soft-float ABI (arm-linux-gnueabi).

On the alias layer

Today armhf aliases to arm, so --target-arch armhf already uses tuxmake/arm_gcc. True.

But this PR is step 1 of a rename. pr-292 flips the alias to arm -> armhf and removes the old arm/armv5 containers.

The image name is built from the canonical arch name after the alias is resolved. So the new containers must exist before the flip, or builds break. That is why we build them first here.

[bhcopeland]

Doesn't this already come from the alias layer?. i.e. --target-arch armhf -t gcc uses tuxmake/arm_gcc and, armv5 uses armv5_gcc.

[roxell]

Today the alias is armhf to arm, so armhf uses tuxmake/arm_gcc. Right.
But this PR is step 1 of a rename. The next commit flips it to arm to armhf, so the build then asks for tuxmake/armhf_gcc. The image name uses the canonical arch name after the alias is resolved, so the alias can't cover this. The alias is what we flip.

So we build the new containers first, then flip, then drop the old ones. They look unused in this PR, but they're needed before the flip or builds break.

[bhcopeland]

Today the alias is armhf to arm, so armhf uses tuxmake/arm_gcc. Right. But this PR is step 1 of a rename. The next commit flips it to arm to armhf, so the build then asks for tuxmake/armhf_gcc. The image name uses the canonical arch name after the alias is resolved, so the alias can't cover this. The alias is what we flip.

So we build the new containers first, then flip, then drop the old ones. They look unused in this PR, but they're needed before the flip or builds break.

Sounds good... Can you get the next PR up so we can do it in a series? And probably update commit message (with the story)

[roxell]

Sounds good... Can you get the next PR up so we can do it in a series? And probably update commit message (with the story)

Today armhf aliases to arm, so it uses tuxmake/arm_gcc. Right.
But this PR is step 1 of a rename. pr-292 flips the alias to arm and removes the old arm/armv5 containers.