Add test handler to count and check generated opcodes. This will be
useful for testing that certain optimizations don't regress.
Also pass a *Config to the Fun constructor so that compile() works.
Change-Id: Iee679e87cf0bc635ddcbe433fc1bd4c1d9c953cc
Reviewed-on: https://go-review.googlesource.com/10502
Reviewed-by: Michael Matloob <michaelmatloob@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Semi-regular merge of tip to dev.ssa.
Complicated a bit by the move of cmd/internal/* to cmd/compile/internal/*.
Change-Id: I1c66d3c29bb95cce4a53c5a3476373aa5245303d
