This patch adds opportunity to detect cpu features via configuration, which can be used later in Makefiles. I'm preparing some tests, which use specific cpu features, so I don't want them to fail on machines without such features. Unfortunately, most of buildbots use configure+make approach, so I propose this patch for configure and makefiles structure.
This additional m4 script is based on "ax_gcc_x86_cpu_support" and "ax_check_x86_features", scripts from autoconf base.
Patch with similar feature for cmake - D38484
Please insert an X86 into the names.