cmd/compile: refactor around HTMLWriter removing logger in favor of Func

Replace HTMLWriter's Logger field with a *Func. Implement Fatalf method
for HTMLWriter which gets the Frontend() from the Func and calls down
into it's Fatalf method, passing the msg and args along. Replace
remaining calls to the old Logger with calls to logging methods on
the Func.

Change-Id: I966342ef9997396f3416fb152fa52d60080ebecb
Reviewed-on: https://go-review.googlesource.com/c/go/+/227277


Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>