Convert more jit phases to opt into common post phase checks

[AndyAyersMS]

There are 20-odd phases that haven't yet been converted to running the common post phase checks. This converts the first half of them.

Note this is a bit of a lie. We actually don't run most checks until morph, but a future change will work on enabling checks throughout the phase list.

I also did a bit of cleanup here and there; most notably we no longer needed fgResetImplicitByRefRefCount as it was just setting the counts the values they already had.

Contributes to #2109.

[ghost]

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
See info in area-owners.md if you want to be subscribed.

Issue Details

---

There are 20-odd phases that haven't yet been converted to running the common post phase checks. This converts the first half of them.

Note this is a bit of a lie. We actually don't run most checks until morph, but a future change will work on enabling checks throughout the phase list.

I also did a bit of cleanup here and there; most notably we no longer needed fgResetImplicitByRefRefCount as it was just setting the counts the values they already had.

Contributes to #2109.

Author:	AndyAyersMS
Assignees:	-
Labels:	area-CodeGen-coreclr
Milestone:	-

[AndyAyersMS]

@dotnet/jit-contrib PTAL

[BruceForstall]

It doesn't look like this change factors into the decision about returning MODIFIED_NOTHING below.

Also, presumably doing this before this phase is equivalent to doing it after, where it was being done before?

[AndyAyersMS]

I haven't been trying to track modifications that we don't check and/or dump anywhere.

[BruceForstall]

(not related to this line)

Interesting that we don't consider removing BBF_REMOVED blocks as modified but I guess that makes sense.

[BruceForstall]

nit

Suggested change

	// return weight [out] - sum of weights for all return and throw blocks
	// returnWeight [out] - sum of weights for all return and throw blocks

[BruceForstall]

Instead of tracking madeChanges you could just use:

Suggested change

	return madeChanges ? PhaseStatus::MODIFIED_EVERYTHING : PhaseStatus::MODIFIED_NOTHING;
	return (compHndBBtabCount > 0) ? PhaseStatus::MODIFIED_EVERYTHING : PhaseStatus::MODIFIED_NOTHING;

[AndyAyersMS]

Sure.

[BruceForstall]

Do you want to un-comment this?

[AndyAyersMS]

I had it that way at one point, but it caused loop table validity asserts.

Will revisit as part of round 2 when I try converting the rest of the phases.

[AndyAyersMS]

SPMI failures are likely from #64497, will merge up next time I push.

[AndyAyersMS]

/azp run runtime-coreclr jitstress

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[AndyAyersMS]

All the jit stress failures are arm/arm64 infra issues. SPMI are timeouts / and or rerun failures because of pre-existing logs.

Going to roll the dice here and say there's no reason to try and get all those green.