See #2993 for an analysis

The was a typo in iamax_sse.S where one of the comparison
was cmpeqps instead of cmpeqss. That misdetected index
for sequences where the minimum value was 0.

fixes #2215

* adapt the C-level reproducer code for some
recent SkylakeX AVX512 kernel issues, provided
by Isuru Fernando and modified by Martin Kroeker,
for usage in the utest suite

* add an Intel SDE SkylakeX emulation utest run to
the Azure CI matrix; a custom Docker build was required
because Ubuntu image provided by Azure does not support
AVX512VL instructions

This is handy for people not using lapack.

* Restore the remaining utests

* Try fork test on Cygwin and Linux only, it hangs on at least ARMv8/Android as well

* Use generic sswap/dswap kernels for NEHALEM 32bit to fix fault found by the restored swap utest

* Disable zdotu test for MS cl to work around runtime error -1073741819 on AppVeyor for now
(probably coding error in the initialization of the complex numbers or wrong choice of zdotu API)

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.