* libc/stdlib/mallocr.c: Include <limits.h>.
(request2size): Change macro to do
unsigned long comparisons and avoid signed overflow.
(mALLOc): Add overflow check for the number of bytes to allocate.
(rEALLOc): Ditto.
* Makefile.in: Regenerate.
* libc/include/_ansi.h (_EXFUN): Define specially for __CYGWIN__.
(_EXPARM): New macro for defining a function parameter.
* libc/include/stdlib.h: Use _EXPARM.
* libc/stdlib/mallocr.c: Don't build cfree for Cygwin.