cmd/compile: remove Node.Escflowsrc, Node.Escretval, Node.Escloopdepth, Node.Esclevel

$ sizeof -p cmd/compile/internal/gc Node
Node 200
$

Change-Id: Iba4e88eac6bee3e2349e818a5a2326deabcb96f9
Reviewed-on: https://go-review.googlesource.com/10528Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

src/cmd/compile/internal/gc/fmt.go

@@ -259,8 +259,8 @@ func Jconv(n *Node, flag int) string {
 		fmt.Fprintf(&buf, " esc(%d)", n.Esc)
 	}
 
-	if n.Escloopdepth != 0 {
-		fmt.Fprintf(&buf, " ld(%d)", n.Escloopdepth)
+	if e, ok := n.Opt.(*NodeEscState); ok && e.Escloopdepth != 0 {
+		fmt.Fprintf(&buf, " ld(%d)", e.Escloopdepth)
 	}
 
 	if c == 0 && n.Typecheck != 0 {

src/cmd/compile/internal/gc/syntax.go

@@ -33,10 +33,6 @@ type Node struct {
 	Curfn *Node // function for local variables
 	Param *Param
 
-	// Escape analysis.
-	Escflowsrc *NodeList // flow(this, src)
-	Escretval  *NodeList // on OCALLxxx, list of dummy return values
-
 	Sym *Sym // various
 
 	Opt interface{} // for optimization passes
@@ -46,9 +42,6 @@ type Node struct {
 
 	Xoffset int64
 
-	// Escape analysis.
-	Escloopdepth int32 // -1: global, 0: return variables, 1:function top level, increased inside function for every loop or label to mark scopes
-
 	Vargen  int32 // unique name for OTYPE/ONAME within a function.  Function outputs are numbered starting at one.
 	Lineno  int32
 	Iota    int32
@@ -59,9 +52,7 @@ type Node struct {
 	// OREGISTER, OINDREG
 	Reg int16
 
-	// most nodes - smaller fields
-	Esclevel Level
-	Esc      uint16 // EscXXX
+	Esc uint16 // EscXXX
 
 	Op          uint8
 	Nointerface bool