non-functional backout for review

[David Xu]

Andrey Chernov wrote:
> Some people complaints that new check in __isctype() is not human readable 
> and requests for backout. Compiler gives almost identical code for old and 
> new excepting non-optimized case where non-human readable one wins. I am a 
> bit tired to change it forth and back, so ask for final consensus here.
> 
> Old one
> 
> return (_c < 0 || _c >= 128) ? 0 :
> 
> New one (requests for backout)
> 
> return (_c & ~0x7F) ? 0 :
> 

I will use a version which compiler can generate optimized code.
the name __isctype already tells what the function is doing. :-)

Regards,
David Xu