[lang] Make dynamic indexing compatible with grouped loop indices of …

…ndrange fors

python/taichi/lang/stmt_builder.py

@@ -396,13 +396,13 @@ def build_grouped_ndrange_for(ctx, node):
         template = '''
 if ti.static(1):
     __ndrange = 0
-    {} = ti.expr_init(ti.Vector([0] * len(__ndrange.dimensions), disable_local_tensor=True))
     ___begin = ti.Expr(0)
     ___end = __ndrange.acc_dimensions[0]
     ___begin = ti.cast(___begin, ti.i32)
     ___end = ti.cast(___end, ti.i32)
     __ndrange_I = ti.Expr(ti.core.make_id_expr(''))
     ti.core.begin_frontend_range_for(__ndrange_I.ptr, ___begin.ptr, ___end.ptr)
+    {} = ti.expr_init(ti.Vector([0] * len(__ndrange.dimensions), dt=ti.i32))
     __I = __ndrange_I
     for __grouped_I in range(len(__ndrange.dimensions)):
         __grouped_I_tmp = 0