runtime: remove unnecessary argument stores for panicIndex etc. on ARM64
If register ABI is used, no need to store the arguments to stack.
I forgot them in CL 323937.
Change-Id: I888af2b547a8fc97d13716bc8e8f3acd5c5bc127
Reviewed-on: https://go-review.googlesource.com/c/go/+/351609
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>