* heap.cc (eval_initial_heap_size): New function fetching the heap

size from the LoaderFlags field in the PE/COFF header.
	(heap_init): Call eval_initial_heap_size rather than
	cygwin_shared->heap_chunk_size to fetch the initial heap size.
	* shared.cc (shared_info::heap_chunk_size): Remove.
	* shared_info.h (class shared_info): Drop heap_chunk member.
	(CURR_SHARED_MAGIC): Update.

winsup/cygwin/shared_info.h

@@ -34,7 +34,7 @@ public:
 /* Data accessible to all tasks */
 
 
-#define CURR_SHARED_MAGIC 0x34e5bfa7U
+#define CURR_SHARED_MAGIC 0x8fe4d9eeU
 
 #define USER_VERSION   1
 
@@ -46,7 +46,6 @@ class shared_info
   LONG version;
   DWORD cb;
  public:
-  DWORD heap_chunk;
   tty_list tty;
   LONG last_used_bindresvport;
   DWORD obcaseinsensitive;