This patch handles native `mma.sync` sizes and enables issuing `ldmatrix` on
largest possible tiles for matrixB. It requires handling
`vector.extract_strided_slice` from vector to ngpu lowering.
Differential Revision: https://reviews.llvm.org/D135749
The ConvertVectorToGpu pass implementation contained a small private
support library for performing various calculations during conversion
between `vector` and `nvgpu.mma.sync` and `nvgpu.ldmatrix` operations.
The support library is moved under `Dialect/NVGPU/Utils` because the
functions have wider utility. Some documentation comments are added or
improved.
Reviewed By: ThomasRaoux
Differential Revision: https://reviews.llvm.org/D135303
