fixed bug power9 strmm . BLAS-TESTER passes

* Add gcc7-generated assembly files for POWER8/9 isa/ica-min/max and POWER9 caxpy

To work around internal compiler errors encountered when compiling the original C source with gcc 4 and 5, and wrong code generated by gcc 8.3.0

* Use gcc-generated assembly instead of original C sources

to work around internal compiler errors encountered with gcc 4.8/5.4 and wrong code generation by gcc 8.3

* Use gcc-generated assembly instead of the original C source

to work around internal compiler errors encountered with gcc 4.8 and 5.4, and wrong code generation by gcc 8.3

* Add gcc7-generated assembler version of caxpy for power8

to work around wrong code generated by gcc 8.3

* Handle CONJ define for caxpyc

* Handle CONJ define for caxpyc

* Add gcc7-generated assembly cdot for POWER9

* Use prebuilt assembly for POWER9 cdot

created with gcc 7.3.1 to work around ICE in older gcc versions

* Exclude POWER9 from DYNAMIC_ARCH when gcc versions is lower than 6

* Update Makefile.system

* Use PROLOGUE macro to ensure correct function name for DYNAMIC_ARCH

* Disable POWER9 with old gcc versions

possible cgemv,caxpy,cdot fix

power9 cgemm/ctrmm. new sgemm 8x16

Signed-off-by: Piotr Kubaj <pkubaj@anongoth.pl>

improved power9 zgemm,sgemm

sgemm/strmm kernel for power9

Add (C)BLAS extension ?sum

as trivial copy of ?asum with the fabs replaced by fmr to preserve code structure

Fixes #2011 (as suggested by davemq), assuming typo by K.Goto

Fixes #2011 (as suggested by davemq) presuming typo by K.Goto

Fixed idamin,icamin choosing the first occurance index of equal minimals

fixes #1571 (the old zrot.S assembly does not handle incx=0 correctly)

* Use generic C implementation of zrot on ppc64/POWER6 to work around utest failure from #1469

z13: improved zgemv_(t|n)_4,zscal,zaxpy

Use lxvd2x instruction instead of lxvw4x.
lxvd2x performs far better on the new POWER architecture than lxvw4x.

Use lxvd2x instruction instead of lxvw4x.
lxvd2x performs far better on the new POWER architecture than lxvw4x.

Use lxvd2x instruction instead of lxvw4x.
lxvd2x performs far better on the new POWER architecture than lxvw4x.

Use lxvd2x instruction instead of lxvw4x.
lxvd2x performs far better on the new POWER architecture than lxvw4x.

Use lxvd2x instruction instead of lxvw4x.
lxvd2x performs far better on the new POWER architecture than lxvw4x.

Use lxvd2x instruction instead of lxvw4x.
lxvd2x performs far better on the new POWER architecture than lxvw4x.