reflect: include the alignment of zero-sized types in stack offsets

This change modifies the reflect ABI assignment algorithm to catch
zero-sized types at the top level of each argument and faux-stack-assign
them. It doesn't actually generate an ABI step, which is unnecessary,
but it ensures that the offsets of further stack-assigned arguments are
aligned to the alignment of that zero-sized argument.

This change is necessary to have the register ABI assignment algorithm
gracefully degrade to ABI0 when no registers are present in the ABI.

Fixes #44377.

Change-Id: Ia95571688a61259302bb3c6d5fb33fbb6b5e8db8
Reviewed-on: https://go-review.googlesource.com/c/go/+/293789
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: Than McIntosh <thanm@google.com>

0 files changed, 0 insertions, 0 deletions