This CL causes the printing of panic values to ensure that all
newlines in the output are immediately followed by a tab, so
that there is no way for a maliciously crafted panic value to
fool a program attempting to parse the traceback into thinking
that the panic value is in fact a goroutine stack.

See https://github.com/golang/go/issues/64590#issuecomment-1932675696

+ release note

Updates #64590
Updates #63455

Change-Id: I5142acb777383c0c122779d984e73879567dc627
Reviewed-on: https://go-review.googlesource.com/c/go/+/581215


Auto-Submit: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>