swizzling assignment

[mighdoll]

swizzing assignment for WGSL or WESL has been mentioned several times on various discussion boards:

v.xz = rotate(v.xz);

(Here's a recent request on matrix.)

Could we support those in WESL and lower them to WGSL? e.g.

// v.xz = rotate(v.xz);
{
  let temp = rotate(v.xz);
  v.x = temp[0];
  v.z = temp[1];
}