TSL: Add while to Loop()

[sunag]

Closes: #28569

Description

Add support for booleans in Loop, to support while().

material.colorNode = Fn( () => {

	const value = float( 0 ).toVar();

	Loop( value.lessThan( 1 ), () => {

		value.addAssign( .1 );

	} );

	return value;

} )();

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	336.08 78.29	336.08 78.29	+0 B +0 B
WebGPU	531.07 147.55	531.16 147.58	+87 B +33 B
WebGPU Nodes	530.54 147.44	530.63 147.48	+87 B +33 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	465.15 112.18	465.15 112.18	+0 B +0 B
WebGPU	602.77 163.53	602.86 163.57	+87 B +39 B
WebGPU Nodes	557.81 152.97	557.89 153.01	+87 B +40 B