df4bd22dd2
Standard C requires tolower to return a character that is !isupper unchanged which was not being done with the macro. The function version does the right thing, so the loss of the macro is no great deal. I didn't eliminate the macros entirely, since X/Open's XPG3 requires _tolower and _toupper with the same semantics. But, like isascii/toascii, they are removed from the namespace if either ANSI_SOURCE or _POSIX_SOURCE is defined.