[dev.regabi] cmd/compile: export all Node fields [generated]

[dev.regabi] cmd/compile: export all Node fields [generated]

The plan was always to export them once we remove the getters
and setters, but do it a bit early, with _ suffixes as needed, so that
the reflection-based ir.Dump can access the fields.

Passes buildall w/ toolstash -cmp.

[git-generate]
cd src/cmd/compile/internal/ir
rf '
	mv AddStringExpr.list AddStringExpr.List_
	mv BlockStmt.list BlockStmt.List_
	mv CallExpr.body CallExpr.Body_
	mv CaseStmt.list CaseStmt.List_
	mv CaseStmt.body CaseStmt.Body_
	mv ClosureExpr.fn ClosureExpr.Func_
	mv CompLitExpr.list CompLitExpr.List_
	mv ForStmt.body ForStmt.Body_
	mv Func.body Func.Body_
	mv IfStmt.body IfStmt.Body_
	mv InlinedCallExpr.body InlinedCallExpr.Body_
	mv RangeStmt.body RangeStmt.Body_
	mv SliceExpr.list SliceExpr.List_
	mv SliceHeaderExpr.lenCap SliceHeaderExpr.LenCap_
	mv TypeSwitchGuard.name TypeSwitchGuard.Name_
'
go generate

Change-Id: I06e65920cecbcc51bea2254f52fcd7d5c5d0dc90
Reviewed-on: https://go-review.googlesource.com/c/go/+/275784
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>