runtime: fix CheckScavengedBitsCleared with randomized heap base
We cannot easily determine the base address of the arena we added the
random padding pages to, which can cause confusing
TestScavengedBitsCleared failures when the arena we padded does not have
the lowest address of all of the arenas.
Instead of attempting to determine the correct arena to ignore when
checking the scav and alloc bits, switch to just tolerating _one_ arena
having mismatches, which is expected when randomizedHeapBase64 is
enabled. Any other number of arenas having mismatches is likely a real
error.
Fixes #75502
Change-Id: Iacc445b2905824f9f71970c7abd33f187793cf39
Reviewed-on: https://go-review.googlesource.com/c/go/+/704855 Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Roland Shoemaker <roland@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>