[RFC] fix: disallow calls on LHS of assignments

it('disallows calls on lhs', () => {
  const getVec = () => {
    'use gpu';
    return d.vec2u(1, 2);
  };

  const fn = () => {
    'use gpu';
    getVec().x = 1;
  };

  expect(tgpu.resolve([fn])).toMatchInlineSnapshot(`
    "fn getVec() -> vec2u {
      return vec2u(1, 2);
    }

    fn fn_1() {
      getVec().x = 1u;
    }"
  `);
});

This is an invalid WGSL. However, I see no way on how this could potentially be useful, so is there really a need handle this?

Start with the inline test using tgpu.resolve and inspect how the shown TypeScript assignment is converted into WGSL. Determine the intended handling for calls on the left-hand side, then update the regression coverage so the generated result no longer permits invalid WGSL.