Don't use once read symbol heuristics in UseDef at warm

[gita-omr]

Don't use once read symbol heuristics in UseDef at warm

- Use onceReadSymbolsIndices at < warm since it helps performance
  without considerably increasing compile time

[vijaysun-omr]

Jenkins build all

[gita-omr]

Made WIP since I still need to run through personal build..

[vijaysun-omr]

Jenkins build all

[fjeremic]

Could we improve the commit message with a reason why this change is being made, or at the very least add a comment to this PR explaining things? I can see someone looking up the history of this change in the future and wondering what drove us to make this change. Also for PRs with one commit we should try to keep the commit title the same as the PR title (+ sentence case capitalization of first work for consistency with other commits).

[gita-omr]

Could we improve the commit message with a reason why this change is being made, or at the very least add a comment to this PR explaining things? I can see someone looking up the history of this change in the future and wondering what drove us to make this change. Also for PRs with one commit we should try to keep the commit title the same as the PR title (+ sentence case capitalization of first work for consistency with other commits).

I can also see that :) Fixed.

[vijaysun-omr]

Jenkins build all

[gita-omr]

Please don't merge yet. I found a personal build failure that I need to debug.

[gita-omr]

I think it was unrelated failure. Please merge if there are no other issues.

[vijaysun-omr]

Heuristic change that looks fine to me and is backed up by data. Checks have passed. Merging.