runtime: add go:yeswritebarrierrec to panic functions
Panic avoids any write barriers in the runtime by checking first
and throwing if called inappropriately, so it is "okay". Adding
this annotation repairs recursive write barrier checking, which
becomes more thorough when the local package naming convention
is changed from "" to the actual package name.
This CL is a prerequisite for a pending code cleanup,
https://go-review.googlesource.com/c/go/+/393715
Updates #51734.
Change-Id: If831a3598c6c8cd37a8e9ba269f822cd81464a13
Reviewed-on: https://go-review.googlesource.com/c/go/+/405900
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: David Chase <drchase@google.com>