[dev.regabi] cmd/compile: exporting, importing, and inlining functions with OCLOSURE

I have exporting, importing, and inlining of functions with closures
working in all cases (issue #28727). all.bash runs successfully without
errors.

Approach:
  - Write out the Func type, Dcls, ClosureVars, and Body when exporting
    an OCLOSURE.

  - When importing an OCLOSURE, read in the type, dcls, closure vars,
    and body, and then do roughly equivalent code to (*noder).funcLit

  - During inlining of a closure within inlined function, create new
    nodes for all params and local variables (including closure
    variables), so they can have a new Curfn and some other field
    values. Must substitute not only on the Nbody of the closure, but
    also the Type, Cvars, and Dcl fields.

Fixes #28727

Change-Id: I4da1e2567c3fa31a5121afbe82dc4e5ee32b3170
Reviewed-on: https://go-review.googlesource.com/c/go/+/283112
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Trust: Dan Scales <danscales@google.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/escape/escape.go b/src/cmd/compile/internal/escape/escape.go
index 5ee6d4f498..883e68a730 100644
--- a/src/cmd/compile/internal/escape/escape.go
+++ b/src/cmd/compile/internal/escape/escape.go
@@ -218,6 +218,10 @@ func Batch(fns []*ir.Func, recursive bool) {
 
 	// Construct data-flow graph from syntax trees.
 	for _, fn := range fns {
+		if base.Flag.W > 1 {
+			s := fmt.Sprintf("\nbefore escape %v", fn)
+			ir.Dump(s, fn)
+		}
 		b.initFunc(fn)
 	}
 	for _, fn := range fns {