Code-gen addcdiv again (#4447)
Summary:
This pull request redoes the addcdiv and addcmul code-gen, and adds a test case to verify that if we reuse the DataCache for scalars.
This needs pytorch/pytorch#92066 to function.
Test Plan:
PJRT_DEVICE=CPU python test/test_operations.py -v -k test_cached_addcdiv
Fixes #4213.
