cmd/compile: enforce strongly typed rules for ARM (8)
add type casting to int32: L148-L156, L774-L778
Toolstash-check successful
Change-Id: Ib6544c1d7853c2811def5b18786e1fc5c18086ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/256097
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Giovanni Bajo <rasky@develer.com>