runtime: tweak js and plan9 to avoid/disable write barrier & gc problems
runtime code for js contains possible write barriers that fail
the nowritebarrierrec check when internal local package naming
conventions are changed. The problem was there all already; this
allows the code to compile, and it seems to work anyway in the
(single-threaded) js/wasm environment. The offending operations
are noted with TODO, which is an improvement.
runtime code for plan9 contained an apparent allocation that was
not really an allocation; rewrite to remove the potential allocation
to avoid nowritebarrierrec problems.
This CL is a prerequisite for a pending code cleanup,
https://go-review.googlesource.com/c/go/+/393715
Updates #51734.
Change-Id: I93f31831ff9b92632137dd7b0055eaa721c81556
Reviewed-on: https://go-review.googlesource.com/c/go/+/405901
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com>