cmd/compile: fix offset-generator for storeOneLoad
storeOneLoad decompose Load that is then stored, the offset value must
be created on the same block with the Load to be dominated, otherwise,
it's unsafe if one does not dominate the other.
Fixes #48026
Change-Id: Iee5e6c5d3e1b09862afe4e65f7bcd771b4c57367
Reviewed-on: https://go-review.googlesource.com/c/go/+/345434
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>