Vulkan backend fails to detect add overflow in some cases

[ailzhang]

The following script doesn't throw an overflow message,

import taichi as ti
ti.init(ti.vulkan, debug=True)

def test_add_overflow():
    ty = ti.u8
    num = 2 ** 7

    @ti.kernel
    def foo(num: ti.u32) -> ty:
        a = ty(num)
        b = ty(num)
        return a + b

    print(foo(num))
    ti.sync()
test_add_overflow()

But this throws as expected:

import taichi as ti
ti.init(ti.vulkan, debug=True)

def test_add_overflow():
    ty = ti.u8
    num = 2 ** 7

    @ti.kernel
    def foo() -> ty:
        a = ty(num)
        b = ty(num)
        return a + b

    print(foo())
    ti.sync()
test_add_overflow()

[bobcao3]

I think this is disabled because of 470 drivers have a wrong implementation of OpIMulHigh or something

[ailzhang]

FWIW this test passed on my workstation with 470.82 but not the other one with 470.161 lol