reflect: fix noswiss builder

Missed this change in CL 681936

Fixes #74808

Change-Id: I30f6402177c5f8efe9bd11d50fad1770a22762c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/691675
Reviewed-by: Cuong Manh Le <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
Reviewed-by: Mark Freeman <[email protected]>
Auto-Submit: Keith Randall <[email protected]>

Author: randall77

src/reflect/map_noswiss.go

@@ -69,7 +69,7 @@ func MapOf(key, elem Type) Type {
 	var imap any = (map[unsafe.Pointer]unsafe.Pointer)(nil)
 	mt := **(**mapType)(unsafe.Pointer(&imap))
 	mt.Str = resolveReflectName(newName(s, "", false, false))
-	mt.TFlag = 0
+	mt.TFlag = abi.TFlagDirectIface
 	mt.Hash = fnv1(etyp.Hash, 'm', byte(ktyp.Hash>>24), byte(ktyp.Hash>>16), byte(ktyp.Hash>>8), byte(ktyp.Hash))
 	mt.Key = ktyp
 	mt.Elem = etyp