* vulkan: sort graph to allow more parallel execution
Add a backend proc to allow the backend to modify the graph. The
vulkan implementation looks at which nodes depend on each other
and greedily reorders them to group together nodes that don't
depend on each other. It only reorders the nodes, doesn't change
the contents of any of them.
With #15489, this reduces the number of synchronizations needed.
* call optimize_graph per-split
While working on the [whisper-cpp](https://conan.io/center/recipes/whisper-cpp) Conan package for ConanCenter, I noticed that enabling the `with_blas` option fails to build due to an issue in the _MKL_ detection logic.
The problem is that the CMake condition currently expands `BLAS_INCLUDE_DIRS` without quotes:
```cmake
if (${BLAS_INCLUDE_DIRS} MATCHES "mkl" AND (${GGML_BLAS_VENDOR} MATCHES "Generic" OR ${GGML_BLAS_VENDOR} MATCHES "Intel"))
```
When `BLAS_INCLUDE_DIRS` is a list (as Conan provides it), the `if()` command receives multiple arguments and produces a CMake error:
```bash
...
-- BLAS found, Includes: /root/.conan2/p/b/openb034c5a6ca927b/p/include;/root/.conan2/p/b/openb034c5a6ca927b/p/include/openblas
CMake Error at ggml/src/ggml-blas/CMakeLists.txt:77 (if):
if given arguments:
"/root/.conan2/p/b/openb034c5a6ca927b/p/include" "/root/.conan2/p/b/openb034c5a6ca927b/p/include/openblas" "MATCHES" "mkl" "AND" "(" "OpenBLAS" "MATCHES" "Generic" "OR" "OpenBLAS" "MATCHES" "Intel" ")"
Unknown arguments specified
...
```
This PR fixes the issue by quoting the variable:
```cmake
if ("${BLAS_INCLUDE_DIRS}" MATCHES "mkl" AND (${GGML_BLAS_VENDOR} MATCHES "Generic" OR ${GGML_BLAS_VENDOR} MATCHES "Intel"))
```
With this change, the whole list is treated as a single string and the regex still works correctly.
Jeff Bolz
Carlos Zoido
AN Long
Kai Pastor
Diego Devesa