cmd/compile/internal/noder: limit the number of goroutine
cmd/compile/internal/noder: limit the number of goroutine

Change-Id: I7f05108fea351a4895dde6090bf86beb822f2c28
GitHub-Last-Rev: e4a2d3a11aa258f2ddf5e39ab4769883f94e3dab
GitHub-Pull-Request: golang/go#45289
Reviewed-on: https://go-review.googlesource.com/c/go/+/305869
Reviewed-by: Keith Randall <8c99c3a9284e493be632950b84cd789d08ed3e9d@golang.org>
Reviewed-by: Matthew Dempsky <e56ac2c500064424afac424d4b5e53bd0570a731@google.com>
Run-TryBot: Keith Randall <8c99c3a9284e493be632950b84cd789d08ed3e9d@golang.org>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

CAFxX/go,cloudflare/go,golang/go,golang/go,CAFxX/go,CAFxX/go,nawawi/go,golang/go,cloudflare/go,nawawi/go,cloudflare/go,cloudflare/go,golang/go,golang/go,nawawi/go,golang/go,CAFxX/go,cloudflare/go,nawawi/go,CAFxX/go,nawawi/go,cloudflare/go,golang/go,nawawi/go,nawawi/go,golang/go,CAFxX/go,cloudflare/go,CAFxX/go,cloudflare/go,nawawi/go,CAFxX/go