Added HFLOAT16 support for RISCV64
Added shgemm_kernel_8x8 for RISCV64_ZVL128B and shgemm_kernel_16x8 for RISCV64_ZVL256B based on HFLOAT16
The instruction sets used are ZVFH and ZFH, which need to be supported by RVV1.0

Related to issue #5279
Co-authored-by Linjin Li <linjin_li@163.com>

Using `OpenMP::OpenMP_LANG` targets for CMake is less error-prone than
passing the compiler and linker flags manually. Furthermore, it allows
the user to customize those flags by setting `OpenMP_LANG_FLAGS`,
`OpenMP_LANG_LIB_NAMES`, and `OpenMP_omp_LIBRARY`.

fixes #2396

fixes #1984

* prebuild.cmake: Put quotes around path names that may contain whitespace
(Copied from alexkaratakis' PR #1295)
* kernel/CMakeLists.txt: Fix common_lapack header inclusion and DYNAMIC_ARCH generation of ?neg_tcopy and ?laswp_ncopy files
* lapack/CMakeLists.txt: Use correct template for ?laswp_(plus,minus) functions

If OpenBLAS is built using add_subdirectory(OpenBlas) as part of another project
then the paths set by CMAKE_XXX_DIR are relative to the parent project
and not the OpenBLAS project.

Instead of generating separate object files for each permutation of
defines for a source file, GenerateNamedObjects now writes an entirely
new source file and inserts the defines as #define c statements.

This solves a problem I ran into with ar.exe where it was refusing to
link objects that had the same filename despite having different paths.

This will generate obj files for SINGLE/DOUBLE/COMPLEX/DOUBLE COMPLEX.

It sets DBLAS_OBJS directly to save a bunch of list appending in the
CMakeLists.txt files.