TSL - WorkgroupInfoNode -> ScopedVariableNode

[cmhhelgeson]

Description

Turn WorkgroupInfoNode into ScopedVariableNode. This PR allow us to

1. Create workgroup address-spacevariables that are not arrays.
2. Manually declare private address-space variables even when the builder.allowGlobalVariables is false.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
Core	388.49 101.98	388.49 101.98	+0 B +0 B
WebGL	372.46 87.93	372.46 87.93	+0 B +0 B
WebGPU	703.52 193.93	703.88 194.04	+363 B +110 B
WebGPU Nodes	701.51 193.63	701.87 193.73	+363 B +103 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	515.87 124.88	515.87 124.88	+0 B +0 B
WebGPU	761.32 204.48	761.89 204.68	+570 B +198 B
WebGPU Nodes	709.98 191.75	710.55 191.96	+570 B +211 B

[sunag]

Do you have an example to demonstrate the issue?

[cmhhelgeson]

Do you have an example to demonstrate the issue?

No, and there is no 'isssue' as of yet, this PR is mostly based out of a desire to translate the single pass prefix sum example seen here: https://github.com/b0nes164/Decoupled-Fallback-Paper/blob/main/artifact/Dawn/Shaders/csdldf.wgsl and referenced in this issue: #34256 (comment). The referenced shader uses workgroup variables, and currently, only workgroup arrays are supported.