as := ir.NewAssignListStmt(c.pos, ir.OAS2,
					[]ir.Node{ir.BlankNode, s.okName},                               // _, ok =
					[]ir.Node{ir.NewTypeAssertExpr(c.pos, s.srcName, c.typ.Type())}) // iface.(type)
				nif := ir.NewIfStmt(c.pos, s.okName, []ir.Node{c.jmp}, nil)
				clauses = append(clauses, typeClause{
					hash: types.TypeHash(c.typ.Type()),
					body: []ir.Node{typecheck.Stmt(as), typecheck.Stmt(nif)},

	// while sema-based impl as M* waitm.
	// Used to be a union, but unions break precise GC.
	key uintptr
}

type funcval struct {
	fn uintptr
	// variable-size, fn-specific data here
}

type iface struct {
	tab  *itab
	data unsafe.Pointer
}

type eface struct {
	_type *_type
	data  unsafe.Pointer
}

func efaceOf(ep *any) *eface {
	return (*eface)(unsafe.Pointer(ep))
}