type precision warning

[evilzhou]

test code:

@ti.kernel
def num_test():
    n = 3
    for i, j in ti.ndrange(n, n):
        print(i, j)

ti.init(arch=ti.cuda, default_ip=ti.i64)
num_test()
ti.sync()

warning content:

type_check.cpp:type_check_store@36] [$64] Local store may lose precision: i32 <- i64

the above test code is just one of many similar cases