runtime: change functype's in and out fields to []*_type

Allows removing a few gratuitous unsafe.Pointer conversions and
parallels the type of reflect.funcType's in and out fields ([]*rtype).

Change-Id: Ie5ca230a94407301a854dfd8782a3180d5054bc4
Reviewed-on: https://go-review.googlesource.com/16163
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/runtime/mfinal.go

@@ -327,11 +327,10 @@ func SetFinalizer(obj interface{}, finalizer interface{}) {
 		throw("runtime.SetFinalizer: second argument is " + *ftyp._string + ", not a function")
 	}
 	ft := (*functype)(unsafe.Pointer(ftyp))
-	ins := *(*[]*_type)(unsafe.Pointer(&ft.in))
-	if ft.dotdotdot || len(ins) != 1 {
+	if ft.dotdotdot || len(ft.in) != 1 {
 		throw("runtime.SetFinalizer: cannot pass " + *etyp._string + " to finalizer " + *ftyp._string)
 	}
-	fint := ins[0]
+	fint := ft.in[0]
 	switch {
 	case fint == etyp:
 		// ok - same type
@@ -356,7 +355,7 @@ func SetFinalizer(obj interface{}, finalizer interface{}) {
 okarg:
 	// compute size needed for return parameters
 	nret := uintptr(0)
-	for _, t := range *(*[]*_type)(unsafe.Pointer(&ft.out)) {
+	for _, t := range ft.out {
 		nret = round(nret, uintptr(t.align)) + uintptr(t.size)
 	}
 	nret = round(nret, ptrSize)

src/runtime/syscall_windows.go

@@ -45,16 +45,16 @@ func compileCallback(fn eface, cleanstack bool) (code uintptr) {
 		panic("compileCallback: not a function")
 	}
 	ft := (*functype)(unsafe.Pointer(fn._type))
-	if ft.out.len != 1 {
+	if len(ft.out) != 1 {
 		panic("compileCallback: function must have one output parameter")
 	}
 	uintptrSize := unsafe.Sizeof(uintptr(0))
-	if t := (**_type)(unsafe.Pointer(ft.out.array)); (*t).size != uintptrSize {
+	if ft.out[0].size != uintptrSize {
 		panic("compileCallback: output parameter size is wrong")
 	}
 	argsize := uintptr(0)
-	for _, t := range (*[1024](*_type))(unsafe.Pointer(ft.in.array))[:ft.in.len] {
-		if (*t).size > uintptrSize {
+	for _, t := range ft.in {
+		if t.size > uintptrSize {
 			panic("compileCallback: input parameter size is wrong")
 		}
 		argsize += uintptrSize

src/runtime/type.go

@@ -84,8 +84,8 @@ type slicetype struct {
 type functype struct {
 	typ       _type
 	dotdotdot bool
-	in        slice
-	out       slice
+	in        []*_type
+	out       []*_type
 }
 
 type ptrtype struct {