container: Improve TreeMap::forEach

[MonsterDruide1]

As suggested by @aboood40091 (#227 (comment)), our implementation of TreeMap::forEach can be slightly simplified to avoid an explicit loop and use recursion instead. Only change from his suggestion: node->mRight must be fetched before fun(node) is called to match the existing behaviour and keep existing functions matched.

---

This change is 

[aboood40091]

Could it be that they original saved left and right in variables at the beginning of the function instead? Does that still match?

[MonsterDruide1]

@aboood40091 No, that does not match. I can move left = node->mLeft before the first usage and re-use that temporary, but mRight needs to be ldred between forEach(left, fun); and fun(node); - that ldr instruction is just after the bl of forEach, and quite a bit before the blr of fun(node);.

[MonsterDruide1]

@aboood40091 Any other comments?

[aboood40091]

All good, and I'll let you decide if you want to use a temporary for left too.

[MonsterDruide1]

Yes, that's still not a bad idea. Adjusted accordingly.

[german77]

@german77 partially reviewed 1 file.
Reviewable status: 0 of 1 files reviewed, all discussions resolved (waiting on @MonsterDruide1).