[release-branch.go1.14] runtime: don't report a pointer alignment error for pointer...

[release-branch.go1.14] runtime: don't report a pointer alignment error for pointer-free base type

Fixes #37905

Change-Id: I8ba9c8b106e16cea7dd25473c7390b0f2ba9a1a5
Reviewed-on: https://go-review.googlesource.com/c/go/+/223781
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-on: https://go-review.googlesource.com/c/go/+/223749