JIT: refine types when creating arg temps to improve devirtualization (#13530)

JIT: refine types when creating arg temps to improve devirtualization (#13530)

The jit will refine the types of temps used to pass arguments to inlinees
when it creates the assignments to these temps.

Unfortunately this is too late to drive devirtualization in the body of
the inlinee, as thes assignments are created after the inlinee body is
imported.

So, add similar refinement logic to the place where the temps are first
created.

Closes #13520.