Constructor module

[nemequ]

As mentioned in travisdowns/uarch-bench#39, it would be nice to have a macro which attempts to register a constructor function.

GLib has some code to do this already for GCC, Windows, and suncc. I'd probably want to at least a C++ version… something like (untested):

#if defined(__cplusplus)
#define PSNIP_CONSTRUCTOR(func_name) \
  static class func_name#_psnip_constructor_class_ { \
    public: \
      func_name#_psnip_constructor_class_(int x) { \
        (void) x; \
        func_name(); \
      } \
  } func_name#_psnip_constructor_(42);
#elif ...
/* ... */
#endif