Merge with Intel ISAL changes from github.com/minio-io/isal

- These changes bring in a much needed Mac OSX port for
    Intel ISAL library
  - At the current stage this MacOSX part of code is
    considered beta
  - pkg/cpu now supports OSX
  - pkg/checksum/crc32c - is still WIP, rest of the packages
    have been validated

pkg/erasure/isal/include/erasure/types.h

@@ -41,7 +41,7 @@
 extern "C" {
 #endif
 
-#ifndef __unix__
+#if !defined(__unix__) && !defined(__APPLE__)
 #ifdef __MINGW32__
 # include <_mingw.h>
 #endif
@@ -59,7 +59,7 @@ typedef unsigned char      UINT8;
 #endif
 
 
-#ifdef __unix__
+#if defined(__unix__) || defined(__APPLE__)
 # define DECLARE_ALIGNED(decl, alignval) decl __attribute__((aligned(alignval)))
 # define __forceinline static inline
 #else