cmd/internal/obj/riscv: fix the encoding for REV8 and ORCB
The instructions are currently encoded and validated using an
iIIEncoding which is incorrect as these instructions do not
take an immediate operand. Encode them instead using an
rIIEncoding as is done for the other two register argument bitmanip
instructions.
Change-Id: Ia4d9c6f6ebd2dfc381935ebc11afa8fc3664232b
Reviewed-on: https://go-review.googlesource.com/c/go/+/637317 Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Joel Sing <joel@sing.id.au> Reviewed-by: Meng Zhuo <mengzhuo1203@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com>