cmd/compile: compute ptrBytes during CalcSize instead of on demand
Compute ptrBytes while computing the size of a type.
Requires an extra field on the type, but means that we don't
have potentially exponential behavior in the PtrDataSize computation.
For #65540.
Change-Id: Ia23c72bbd996730baddd32d9ed46cfc00c3472ee
Reviewed-on: https://go-review.googlesource.com/c/go/+/571543 Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com>