cmd/compile: convert Type.Trecur to a boolean flag

Change-Id: I162e86e5f92c8b827a74ee860d16abadf83bc43e
Reviewed-on: https://go-review.googlesource.com/38910
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

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

@@ -1426,10 +1426,10 @@ func lookdot0(s *Sym, t *Type, save **Field, ignorecase bool) int {
 // embedded fields at depth d, so callers can decide whether to retry at
 // a greater depth.
 func adddot1(s *Sym, t *Type, d int, save **Field, ignorecase bool) (c int, more bool) {
-	if t.Trecur != 0 {
+	if t.Recur() {
 		return
 	}
-	t.Trecur = 1
+	t.SetRecur(true)
 
 	var u *Type
 	d--
@@ -1471,7 +1471,7 @@ func adddot1(s *Sym, t *Type, d int, save **Field, ignorecase bool) (c int, more
 	}
 
 out:
-	t.Trecur = 0
+	t.SetRecur(false)
 	return c, more
 }
 
@@ -1585,10 +1585,10 @@ func expand0(t *Type, followptr bool) {
 }
 
 func expand1(t *Type, top, followptr bool) {
-	if t.Trecur != 0 {
+	if t.Recur() {
 		return
 	}
-	t.Trecur = 1
+	t.SetRecur(true)
 
 	if !top {
 		expand0(t, followptr)
@@ -1615,7 +1615,7 @@ func expand1(t *Type, top, followptr bool) {
 	}
 
 out:
-	t.Trecur = 0
+	t.SetRecur(false)
 }
 
 func expandmeth(t *Type) {

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

@@ -153,9 +153,8 @@ type Type struct {
 	Sym    *Sym  // symbol containing name, for named types
 	Vargen int32 // unique name for OTYPE/ONAME
 
-	Etype  EType // kind of type
-	Trecur uint8 // to detect loops
-	Align  uint8 // the required alignment of this type, in bytes
+	Etype EType // kind of type
+	Align uint8 // the required alignment of this type, in bytes
 
 	flags bitset8
 }
@@ -166,6 +165,7 @@ const (
 	typeBroke                 // broken type definition
 	typeNoalg                 // suppress hash and eq algorithm generation
 	typeDeferwidth
+	typeRecur
 )
 
 func (t *Type) Local() bool      { return t.flags&typeLocal != 0 }
@@ -173,12 +173,14 @@ func (t *Type) NotInHeap() bool  { return t.flags&typeNotInHeap != 0 }
 func (t *Type) Broke() bool      { return t.flags&typeBroke != 0 }
 func (t *Type) Noalg() bool      { return t.flags&typeNoalg != 0 }
 func (t *Type) Deferwidth() bool { return t.flags&typeDeferwidth != 0 }
+func (t *Type) Recur() bool      { return t.flags&typeRecur != 0 }
 
 func (t *Type) SetLocal(b bool)      { t.flags.set(typeLocal, b) }
 func (t *Type) SetNotInHeap(b bool)  { t.flags.set(typeNotInHeap, b) }
 func (t *Type) SetBroke(b bool)      { t.flags.set(typeBroke, b) }
 func (t *Type) SetNoalg(b bool)      { t.flags.set(typeNoalg, b) }
 func (t *Type) SetDeferwidth(b bool) { t.flags.set(typeDeferwidth, b) }
+func (t *Type) SetRecur(b bool)      { t.flags.set(typeRecur, b) }
 
 // MapType contains Type fields specific to maps.
 type MapType struct {