math/big: add tests for allocation during multiply
Test that big.Int.Mul reusing the same target is not allocating
temporary garbage during its computation. That code is going
to be modified in an upcoming CL.
Change-Id: I3ed55c06da030282233c29cd7af2a04f395dc7a2
Reviewed-on: https://go-review.googlesource.com/c/go/+/652056
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Russ Cox <rsc@golang.org>