cmd/compile: convert asmlist to []*Node

Updates #14473.

Change-Id: I88745c2a6119dea3b81b57299e70a2a7e4c584a8
Reviewed-on: https://go-review.googlesource.com/20272
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

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

@@ -27,7 +27,7 @@ func exportf(format string, args ...interface{}) {
 	}
 }
 
-var asmlist *NodeList
+var asmlist []*Node
 
 // Mark n's symbol as exported
 func exportsym(n *Node) {
@@ -89,7 +89,7 @@ func autoexport(n *Node, ctxt Class) {
 	}
 	if asmhdr != "" && n.Sym.Pkg == localpkg && n.Sym.Flags&SymAsm == 0 {
 		n.Sym.Flags |= SymAsm
-		asmlist = list(asmlist, n)
+		asmlist = append(asmlist, n)
 	}
 }
 
@@ -565,17 +565,12 @@ func importtype(pt *Type, t *Type) {
 }
 
 func dumpasmhdr() {
-	var b *obj.Biobuf
-
 	b, err := obj.Bopenw(asmhdr)
 	if err != nil {
 		Fatalf("%v", err)
 	}
-	fmt.Fprintf(b, "// generated by %cg -asmhdr from package %s\n\n", Thearch.Thechar, localpkg.Name)
-	var n *Node
-	var t *Type
-	for l := asmlist; l != nil; l = l.Next {
-		n = l.N
+	fmt.Fprintf(b, "// generated by compile -asmhdr from package %s\n\n", localpkg.Name)
+	for _, n := range asmlist {
 		if isblanksym(n.Sym) {
 			continue
 		}
@@ -584,7 +579,7 @@ func dumpasmhdr() {
 			fmt.Fprintf(b, "#define const_%s %v\n", n.Sym.Name, Vconv(n.Val(), obj.FmtSharp))
 
 		case OTYPE:
-			t = n.Type
+			t := n.Type
 			if t.Etype != TSTRUCT || t.Map != nil || t.Funarg {
 				break
 			}