* dlmalloc.c: New file. Port of Doug Lea's malloc

* dlmalloc.h: Ditto.
* Makefile.in: Add support for MALLOC_DEBUG
* config.h.in: Ditto.
* winsup.h: Ditto.
* configure.in: Add --enable-malloc-debugging option.
* configure: Regenerate.
* debug.h: Include declarations for debugging malloc.
* tty.cc (grantpt): Fix definition.
(unlockpt): Ditto.

winsup/cygwin/winsup.h

@@ -58,7 +58,9 @@ extern char case_folded_lower[];
 extern char case_folded_upper[];
 #define cyg_toupper(c) (case_folded_upper[(unsigned char)(c)])
 
+#ifndef MALLOC_DEBUG
 #define cfree newlib_cfree_dont_use
+#endif
 
 #define WIN32_LEAN_AND_MEAN 1
 #define _WINGDI_H