This patch adds an intrinsic for setmaxnreg PTX instruction.
* PTX Doc link for this instruction:
https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#miscellaneous-instructions-setmaxnreg
* The i32 argument, an immediate value, specifies the actual
absolute register count for the instruction.
* The `setmaxnreg` instruction is available in SM90a.
So, this patch adds 'hasSM90a' predicate to use in
the NVPTX backend.
* lit tests are added to verify the lowering of the intrinsic.
* Verifier logic (and tests) are added to test the register
count range and divisibility-by-8 requirements.
Signed-off-by: Durgadoss R <durgadossr@nvidia.com>
340cc1702e