C++ PATCH: cleanup DEBUG_BINDING_LEVELS code

[Mark Mitchell]

>   While working on the name-lookup performance issue, I came to turn
> on DEBUG_BINDING_LEVELS and realize that nobody has been turning it on
> for some while.  This patch (which was dormant in my local tree)
> cleans up the DEBUG_BINDING_LEVELS code  so as to make it bootstrap
> again with the -Werror option.  

Why can't we just use this idiom:

  #ifndef DEBUG_BINDING_LEVELS
  #define DEBUG_BINDING_LEVELS 0
  #else
  #define DEBUG_BINDING_LEVELS 1
  #endif

  ...

  if (DEBUG_BINDING_LEVELS) { 
  ...
  }

Why do we need another macro?

-- 
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com