* cygheap.cc (init_cheap): Set aside space for heap walk pointer.

(_csbrk): Make logic for detecting when to alloc cognizant of initialization
condition.
(_cmalloc): Use a structure to hold bucket size and heap chain pointer.  Store
pointer to next freed block in bucket size location so that it will be easy to
see if a block is allocated.
(_cfree): Store pointer to next freed block in bucket size location.
(_crealloc): Use macro to retrieve bucket size.
(cygheap_init): Eliminate.
(cygheap_fixup_in_child): Add second argument to determine if we were execed or
not.  In execed case, walk the heap, cleaning up any orphaned blocks.
* cygheap.h: Add a "MAX" value to cygheap_types.  Remove cygheap_init
declaration.  Accomodate new argument to cygheap_fixup_in child.
* fork.cc (fork): Accomodate extra argument to cygheap_fixup_in_child.
* dcrt0.cc (dll_crt0_1): Ditto.  Remove call to cygheap_init.

winsup/cygwin/fork.cc

@@ -571,7 +571,7 @@ fork ()
 
       MALLOC_CHECK;
 
-      cygheap_fixup_in_child (hParent);
+      cygheap_fixup_in_child (hParent, 0);
       fdtab.fixup_after_fork (hParent);
       signal_fixup_after_fork ();
       exec_fixup_after_fork ();