introduce a few configs for DATAS fine tuning

[Maoni0]

also, if the GCGen0MaxBudget config is specified, always honor it including for DATAS.

I will be submitting a doc PR to document these configs.

[Copilot]

Pull Request Overview

This PR introduces several new configuration options for fine-tuning the DATAS (Dynamic Adaptation To Application Sizes) feature in the garbage collector. The main purpose is to provide more granular control over gen0 budget calculations and growth factors used by DATAS.

Key changes include:

• Addition of three new configuration parameters for controlling gen0 growth relative to stable SOH size
• Modification of GCGen0MaxBudget behavior to always honor the specified value when set, including for DATAS
• Updates to the gen0 budget computation logic to use configurable parameters instead of hardcoded values

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/coreclr/gc/gcconfig.h	Adds three new DATAS configuration options and exposes GCGen0MaxBudget as a public configuration
src/coreclr/gc/gcpriv.h	Introduces configurable parameters for gen0 growth computation and refactors variable names for clarity
src/coreclr/gc/gc.cpp	Implements configuration parameter initialization, validation logic, and modifies gen0 budget handling to always honor GCGen0MaxBudget

Comments suppressed due to low confidence (3)

[Maoni0]

@mangod9 these are the configs I mentioned; PTAL.

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[mangod9]

Looks good, apart from the config naming. If that is the best naming for now its ok, we can change it later.

[Maoni0]

/backport to release/10.0-rc1

[github-actions]

Started backporting to release/10.0-rc1: https://github.com/dotnet/runtime/actions/runs/17051326822

[github-actions]

@Maoni0 an error occurred while backporting to "release/10.0-rc1", please check the run log for details!

Validation Failed: {"resource":"PullRequest","code":"custom","message":"No commits between release/10.0-rc1 and backport/pr-118762-to-release/10.0-rc1"}