When combining a byteswap and a load, the resulting combined op
must go in the load's block, not the byteswap's block, as the load
has a memory argument that might only be valid in its original block.
Fixes #59973
Change-Id: Icd84863ef3a9ca1fc22f2bb794a003f2808c746f
Reviewed-on: https://go-review.googlesource.com/c/go/+/492616
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Wayne Zuo <wdvxdr@golangcn.org> Reviewed-by: Keith Randall <khr@google.com>