* vulkan : use ggml_row_size for types with a per-row scale
Types that declare a row_meta_size store a per-row scale ahead of the row's
blocks, so a row is not ggml_type_size()*ne/ggml_blck_size() bytes. This
under-sized src0 in the four quantized mat-mul paths, and made
ggml_vk_dim01_contiguous() report such a tensor non-contiguous, which in turn
made supports_op reject it. No change for row_meta_size == 0.
* vulkan : add IQ4_KS and IQ4_KT support
A row of these types is one f32 scale followed by the row's blocks, so rows are
not a whole number of blocks apart and the usual block-indexed addressing does
not work. They are read through a uint32_t alias of binding 0 and addressed by
word; types.comp holds the alias, the stride and the decode, so each shader only
expresses its own addressing and no push constant layouts change.
Covers to_fp16, get_rows, mul_mat_vec (incl. MUL_MAT_ID) and scalar + coopmat1
mul_mm. get_rows addresses by row rather than through nb01/02/03, which cannot
express a per-row scale, so supports_op accepts only a contiguous src0 for these
two types. coopmat2 is excluded because coopMatLoadTensorNV addresses through a
uniform grid tensor layout, which cannot describe the row prefix; the two
mat-mat getters return nullptr there and the callers fall back to F16.
* tests : add IQ4_KS/IQ4_KT decode validation
Re-implements in C++ the indexing each of the four shader families uses and
diffs it against ggml's to_float over several row and block counts. CPU only: it
validates the format transcription, not the compiled shaders.
Guy Barel