utest: Add tests for zscal

Introduced recently when adding new test cases for ZSCAL

- include cblas is needed for cblas_zscal
- ASSERT macro does not exist
- missing closing )

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

sgemv cgemv pairs

already provided conditionally by common.h via openblas_utest.h
Unconditional inclusion breaks older Android and similar platforms that use OPENBLAS_COMPLEX_STRUCT

With glibc 2.5 one must have #define _XOPEN_SOURCE >= 500 to use wait.
But reading glibc code this is actually needed only if stdlib.h was
included before sys/wait.h. This was the case here through
openblas_utest.h. So changing include fix compilation on RHEL5 and
should ne hurt with more recent distro.

* Problem found when using with gcc 5.5 and 4.7.2 on RHEL5/CENTOS5
* Fix #1519

_snprintf_s takes an additional (size) argument, so is no direct replacement.
(Note that this code is currently unused - the two instances of snprintf here are within ifdef blocks that are not compiled for MSVC)

This is handy for people not using lapack.

Do not try to build the fork utest when NO_CBLAS=1