runtime: fix -Wsign-compare warnings

[kkysen]

Projects being rewritten and compiled may have warnings/errors like this turned on, so it's simpler to just fix them.

Note that this doesn't set -Werror=sign-compare in cmake because that'll apply to all of the tests, too. We just want to make sure that included headers work under different possible warning/error configurations a project might set.

[ayrtonm]

Maybe we should build with -Wsign-compare as well? I mean we already build with ubsan to catch potential issues.

[kkysen]

Maybe we should build with -Wsign-compare as well? I mean we already build with ubsan to catch potential issues.

Sure, we can do that, too. I think the -Wsign-compare came from something like -Wall so we should probably just do that.

[ayrtonm]

-Wall would be nice but it's not a priority so let's stick to just -Wsign-compare for now. Also when we update the docs we should keep track of which flags are required and which are just nice-to-haves.

[ayrtonm]

LGTM after adding -Wsign-compare here.

[kkysen]

@ayrtonm, hmm, now I'm hitting other sign-compares in the other examples/tests. Is there a way I can only enable -Wsign-compare in cmake some of the time, because this is something that we want to work without errors no matter what flags the downstream user is setting. Maybe it's easier to just not set -Werror=sign-compare for us?

[ayrtonm]

Sorry that was for all compartments. This is probably where we want the flag so it'll only apply to libia2.a https://github.com/immunant/IA2-Phase2/blob/main/runtime/libia2/CMakeLists.txt#L5

[ayrtonm]

Actually the last place I linked wouldn't apply it to the original places you fixed, only the sources in runtime/libia2 so I'm fine leaving the flag out for now.

[kkysen]

Merging now since @ayrtonm already approved this version and we decided not to set -Werror=sign-compare anymore.