[dev.typeparams] cmd/compile: scaffolding for export data experiments
This CL adds a simple framework for augmenting the current export data
format by writing out additional data *after* the existing data, with
an extra header before it that current readers ignore.
In particular, this is used by unified IR to be able to experiment and
iterate on export data designs without having to keep the
go/internal/gcimporter and x/tools/go/gcexportdata importers in
sync. Instead, they simply continue reading the existing data written
out by typecheck/iexport.go.
Change-Id: I883211c2892e2c7dec758b85ff6bc31b244440a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/327169
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Trust: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>