[BUG] fp_quantizer is not correctly built when non-jit installation

[twaka]

Describe the bug
fp_quantizer is not correctly built when non-jit installation.

To Reproduce
Steps to reproduce the behavior:

DS_BUILD_FP_QUANTIZER=1 pip install deepspeed

install will succeed but

from deepspeed.ops.fp_quantizer import FP_Quantize
FP_Quantize()

will raise ImportError: dynamic module does not define module export function (PyInit_fp_quantizer_op)

Expected behavior

Renaming csrc/fp_quantizer/quantize.cu may solve the issue.
This restriction seems to be cause of the bug.

Note that setuptools cannot handle files with the same name but different extensions
https://pytorch.org/tutorials/advanced/cpp_extension.html

[loadams]

Thanks for pointing this out @twaka - we will take a look

[loadams]

@twaka Can you try #5577?