TSL: Fix Fn as parameter

[sunag]

Fixes #31212

Description

Fix Fn as parameter. e.g:

const bar = Fn(([r, g, b]) => {
    return vec3(r, g, b)
})

const foo = Fn(([baz]) => {
    return baz(0.1, 0.2, 0.3)
})

const material = new THREE.NodeMaterial()
material.fragmentNode = foo(bar)

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	337.4 78.67	337.4 78.67	+0 B +0 B
WebGPU	553.81 153.47	553.83 153.48	+19 B +10 B
WebGPU Nodes	553.16 153.32	553.18 153.33	+19 B +10 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	468.59 113.32	468.59 113.32	+0 B +0 B
WebGPU	628.77 170.2	628.78 170.21	+19 B +11 B
WebGPU Nodes	583.62 159.54	583.64 159.55	+19 B +12 B

[mrdoob]

Should we release 0.177.1 with this fix?

[sunag]

I'm not sure if it's necessary because it's not very common to use TSL functions as parameters yet. Maybe we could wait in case someone else reports this? Unless we have other pending fixes.

[mrdoob]

Okay!