(Z systems Z13) small fixes, some (i(dz)amin,i(dz)amax,(dz)dot,(dz)asum) mikrokernels…

Address warnings #1357

Tag %1 and %2 as both input and output operands

fix from #1292 extended to the other gemv microkernels

Tag %1 and %2 as both input and output

Address few more warnings

The inline assembly modifies its input operands, so mark them as output to avoid surprises with optimization. Fixes #1292

related to issue #1332

The testcase from #1332 exposes a problem in daxpy_microk_haswell-2.c that is not seen with
any of the other Intel x86_64 microkernels.

* dead increments in driver/level2

* dead increments in kernel/generic

* part dead increments in kernel/x86_64

Add trivially optimized DSDOT for POWER8

Add optimized dsdot to all other x86_64 kernels that use sdot.c

Clean up spurious unused variables in the kernels

l2 cache size is not universally needed to assign default unrolling limits, but neither putting its declaration inside an ifdef nor cloning it into all ifdef sections that need it really makes sense here.

(Trivial) optimized dsdot implementation for HASWELL

While debugging/profiling applications using perf or other tools, the
kernels appear scattered in the profile reports. This is because the labels
within the kernels are not local and each label is shown as a separate
function.

To avoid this, all the labels within the kernels are changed to local
labels.

* 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

Fix out-of-bounds memory accesses exposed by xccblat3 testcase