1. Use getauxval instead of cpucfg to test hardware capability.
2. Remove unnecessary code and option for compiler check in c_check.

This patch fixes errors when using Open XL C compiler on AIX.
Tested with gcc/xlf and ibm-clang/xlf compiler combinations.

Historically the GNU mktemp was the first one which doesn't requires
`-t` to create a directory.

Here I've introduced a fallback when `-t` is required.

For example MacPorts contains similar patch: bbe8abfe26/math/OpenBLAS/files/patch-MacOSX-mktemp.diff

fix for #3989

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>

Due to recent perl script conversion, there are some build
errors when compiling openblas with advance toolchain compilers.

additionla fix for upcoming OSX on ARM64 related to #2804, as suggested by fxcoudert in #2805

"unrecognized command line option ‘-mmsa’"

* Add automatic fixups for OSX/IOS cross-compilation

* Add OSX/IOS cross-compilation test to Travis CI

* Handle platforms that lack hwcap.h by falling back to ARMV8

* Fix PROLOGUE for OSX/IOS

by catching and working around failures to load modules, and avoiding object-oriented syntax in tempfile creation.
Fixes #1989