cmd/compile/internal/ssa: ExternSymbol's Typ field is unused too

Change-Id: I5b692eb0586c40f3735a6b9c928e97ffa00a70e6
Reviewed-on: https://go-review.googlesource.com/40471
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/ssa.go

@@ -1380,13 +1380,13 @@ func (s *state) expr(n *Node) *ssa.Value {
 		len := s.newValue1(ssa.OpStringLen, types.Types[TINT], str)
 		return s.newValue3(ssa.OpSliceMake, n.Type, ptr, len, len)
 	case OCFUNC:
-		aux := s.lookupSymbol(n, &ssa.ExternSymbol{Typ: n.Type, Sym: Linksym(n.Left.Sym)})
+		aux := s.lookupSymbol(n, &ssa.ExternSymbol{Sym: Linksym(n.Left.Sym)})
 		return s.entryNewValue1A(ssa.OpAddr, n.Type, aux, s.sb)
 	case ONAME:
 		if n.Class == PFUNC {
 			// "value" of a function is the address of the function's closure
 			sym := Linksym(funcsym(n.Sym))
-			aux := s.lookupSymbol(n, &ssa.ExternSymbol{Typ: n.Type, Sym: sym})
+			aux := s.lookupSymbol(n, &ssa.ExternSymbol{Sym: sym})
 			return s.entryNewValue1A(ssa.OpAddr, types.NewPtr(n.Type), aux, s.sb)
 		}
 		if s.canSSA(n) {
@@ -2826,7 +2826,7 @@ func init() {
 		sys.ARM64)
 	makeOnesCount := func(op64 ssa.Op, op32 ssa.Op) func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
 		return func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
-			aux := s.lookupSymbol(n, &ssa.ExternSymbol{Typ: types.Types[TBOOL], Sym: Linksym(syslook("support_popcnt").Sym)})
+			aux := s.lookupSymbol(n, &ssa.ExternSymbol{Sym: Linksym(syslook("support_popcnt").Sym)})
 			addr := s.entryNewValue1A(ssa.OpAddr, types.Types[TBOOL].PtrTo(), aux, s.sb)
 			v := s.newValue2(ssa.OpLoad, types.Types[TBOOL], addr, s.mem())
 			b := s.endBlock()
@@ -3197,7 +3197,7 @@ func (s *state) addr(n *Node, bounded bool) *ssa.Value {
 		switch n.Class {
 		case PEXTERN:
 			// global variable
-			aux := s.lookupSymbol(n, &ssa.ExternSymbol{Typ: n.Type, Sym: Linksym(n.Sym)})
+			aux := s.lookupSymbol(n, &ssa.ExternSymbol{Sym: Linksym(n.Sym)})
 			v := s.entryNewValue1A(ssa.OpAddr, t, aux, s.sb)
 			// TODO: Make OpAddr use AuxInt as well as Aux.
 			if n.Xoffset != 0 {
@@ -4744,7 +4744,7 @@ func (e *ssafn) StringData(s string) interface{} {
 		e.strings = make(map[string]interface{})
 	}
 	data := stringsym(s)
-	aux := &ssa.ExternSymbol{Typ: types.Idealstring, Sym: data}
+	aux := &ssa.ExternSymbol{Sym: data}
 	e.strings[s] = aux
 	return aux
 }

src/cmd/compile/internal/ssa/value.go

@@ -237,7 +237,6 @@ func (v *Value) isGenericIntConst() bool {
 // ExternSymbol is an aux value that encodes a variable's
 // constant offset from the static base pointer.
 type ExternSymbol struct {
-	Typ Type // Go type
 	Sym *obj.LSym
 	// Note: the offset for an external symbol is not
 	// calculated until link time.

src/cmd/compile/internal/ssa/writebarrier.go

@@ -93,7 +93,7 @@ func writebarrier(f *Func) {
 			if sp == nil {
 				sp = f.Entry.NewValue0(initpos, OpSP, f.Config.Types.Uintptr)
 			}
-			wbsym := &ExternSymbol{Typ: f.Config.Types.Bool, Sym: f.fe.Syslook("writeBarrier")}
+			wbsym := &ExternSymbol{Sym: f.fe.Syslook("writeBarrier")}
 			wbaddr = f.Entry.NewValue1A(initpos, OpAddr, f.Config.Types.UInt32Ptr, wbsym, sb)
 			writebarrierptr = f.fe.Syslook("writebarrierptr")
 			typedmemmove = f.fe.Syslook("typedmemmove")
@@ -176,7 +176,7 @@ func writebarrier(f *Func) {
 			ptr := w.Args[0]
 			var typ interface{}
 			if w.Op != OpStoreWB {
-				typ = &ExternSymbol{Typ: types.Uintptr, Sym: w.Aux.(Type).Symbol()}
+				typ = &ExternSymbol{Sym: w.Aux.(Type).Symbol()}
 			}
 			pos = w.Pos