Adding DATAS GC info to !eeversion

[mahamr]

Background and Motivation

Debugging and being caught off-guard :)

Proposed Feature

When debugging dumps with DATAS GC enabled, it would be great to have !eeversion include that and related information in its output. This could be especially helpful for .NET 8 where DATAS is opt-in, but having extra DATAS-focused output like current heap count vs. max heap count would be nice in general.

Usage Examples

Right now, with a dump of a .NET 8 app with DATAS GC opted-in (and GC running), this is what !eeversion shows:

0:000> !eeversion
8.0.624.26715 free
8,0,624,26715 @Commit: 3b8b000a0e115700b18265d8ec8c6307056dc94d
Server mode with 1 gc heaps
In plan phase of garbage collection
SOS Version: 9.0.11.3101 retail build

That "Server mode with 1 gc heaps" caught me off-guard initially (don't recall having ever seen that before but I might be wrong), but then I checked for DATAS GC and it was enabled (this is from a customer dump and that info had not yet been shared).

If the output could show something like the below, that would be great:

0:000> !eeversion
8.0.624.26715 free
8,0,624,26715 @Commit: 3b8b000a0e115700b18265d8ec8c6307056dc94d
Using DATAS GC 
DATAS: Max heap count: 2
DATAS: Current heap count: 1
In plan phase of garbage collection
SOS Version: 9.0.11.3101 retail build

Perhaps along with any other information that might be helpful, like the metrics that led to the current heap count changing or not changing, etc.

[mikem8361]

That sounds good, but !sosstatus might be a better place (C# command, easier to write and already displays a bunch other things).

We may need a new DAC and CLRMD APIs to get the DATAS info.

[tommcdon]

When debugging dumps with DATAS GC enabled, it would be great to have !eeversion include that and related information in its output.
We may need a new DAC and CLRMD APIs to get the DATAS info.

FYI @Maoni0 @cshung

[cshung]

Earlier I was doing that and looking for a use case, now we have one.

dotnet/runtime#107115

[mikem8361]

Andrew, that PR doesn't help SOS display the DATAS info without a new DAC API.