This is intended to help debug compiler problems that pop
up in the bootstrap phase of make.bash.  GO_GCFLAGS does not
normally apply there.  Options-for-all phases is intended
to allow crude tracing (and full timing) by turning on timing
for all phases, not just one.

Phase names can also be specified using a regular expression,
for example
BOOT_GO_GCFLAGS=-d='ssa/~^.*scc$/off' \
GO_GCFLAGS='-d=ssa/~^.*scc$/off' ./make.bash

I just added this because it was the fastest way to get
me to a place where I could easily debug the compiler.

Change-Id: I0781f3e7c19651ae7452fa25c2d54c9a245ef62d
Reviewed-on: https://go-review.googlesource.com/20775Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>