Added ASM code patching when loading

For CNv2 variants with different iterations and memory size.

src/Mem_unix.cpp

@@ -87,3 +87,19 @@ void Mem::release(MemInfo &info)
         _mm_free(info.memory);
     }
 }
+
+
+void* Mem::allocate_executable_memory(size_t size)
+{
+#   if defined(__APPLE__)
+    return mmap(0, size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANON, -1, 0);
+#   else
+    return mmap(0, size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+#   endif
+}
+
+
+void Mem::FlushInstructionCache(void* p, size_t size)
+{
+    __builtin___clear_cache(reinterpret_cast<char*>(p), reinterpret_cast<char*>(p) + size);
+}