runtime: ensure that we don't scan noscan objects

We claim to not maintain pointer bits for noscan objects. But in fact
we do, since whenever we switch a page from scannable to noscan, we
call heapBits.initSpan which zeroes the heap bits.

Switch to ensure that we never scan noscan objects. This ensures that
we don't depend on the ptrbits for noscan objects. That fixes a bug
in the 1-bit bitmap CL which depended on that fact.

Change-Id: I4e66f582605b53732f8fca310c1f6bd2892963cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/422435
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

0 files changed, 0 insertions, 0 deletions