CCopyType has no effect

[Andreas-Bur]

The CHERI-RISC-V instruction CCopyType cd, cs1, cs2 seems to be not working if cd is the same as cs1. Here a small PoC:

# Init FPU

  lui	t4, 2
  csrw	mstatus, t4

# Program start

  cspecialrw	c1, ddc, cnull
  ccopytype	c2, c1, cnull
  ccopytype	c1, c1, cnull
  cgettag	x3, c1 # Stores 1 in x3
  cgettag	x4, c2 # Stores 0 in x4

I would have expected the tag of c1 to be cleared. The tag also doesn't seem to be copied in a valid case.