increase upper bounds of main zig executable to 9G

[Jan200101]

On Fedora 42 aarch64 memory usage peaked at 8736403456 bytes

https://zsf.zulipchat.com/#narrow/channel/454360-compiler/topic/exceeding.20the.20declared.20upper.20bound/near/513471272

[Jan200101]

hmm, I'm actually not entirely sure if this is the best idea.
the build runner checks if max_rss is larger than the available system memory and fails if it is, bumping this limit to 9G would make it impossible to compile on anything else... maybe this is just something that I'll need to carry as a downstream patch.

[Jan200101]

Andrew Kelley| said:

users of `zig build` can pass this flag to ignore that check:
```
  --maxrss <bytes>             Limit memory usage (default is to use available memory)
```

so its probably fine to merge

[erikarvstedt]

One could also make the argument to not merge this and set --maxrss on Fedora aarch64 instead.

[Jan200101]

One could also make the argument to not merge this and set --maxrss on Fedora aarch64 instead.

andrew made the decision that it should be bumped, see the zulip link in the description.

its also been bumped in the past due to rising memory demands #21916
it might make more sense to add it to the CMakeLists since thats where the memory consumption is biggest and its already done for x86 mingw, but that is not for me to decide

---

I tried to understand the code and apparently the --maxrss flag is only useful for setting the max amount of memory the build runner considers usable (even if there isn't as much memory available) while the per-step max_rss is enforced regardless of the flag value.

So there is no alternative to this.