Removal of block pointer dependency

[etiotto]

Triton upstream will sunset support for block pointers. Conversely the new tensor descriptor API will be "blessed" and no longer experimental.

In order to transition to use tensor descriptors we need:

1. a transition plan to convert tensor descriptor into block pointers (internally)
2. make our BE transformation work flawlessly with the tensor descriptor API

(1) will be done first and will allow us to merge in our branch the removal of the python API dealing with block ptrs (and possible support in the Triton dialect for the block ptr operations)

(2) will be done after (1)

[alexbaden]

What is the difference between converting tensor descriptor to block ptr and supporting tensor descriptor natively?

[etiotto]

What is the difference between converting tensor descriptor to block ptr and supporting tensor descriptor natively?

The former allows us to use the TTGIR passes unchanged (because they already support block pointers). The later would require us to adapt TTGIR passes that now expect block pointers to work for tensor descriptors.