#1 avoid 'conditional expression is constant' warning

[Anonymous]

May I suggest the use of "while(__LINE__ == -1)" instead of while(0) for
PROFILE_CODE and _PROFILE_ZONE_BEGIN ?
I would get rid of the 'conditional expression is constant' warning, which
can be a useful one (so the user may be reluctant to disable it).

I don't know if I'm posting in the right section, sorry about that if it's
the case.