xglobals: Add __MCF_mresize_0()

mcfgthread/thread.c

@@ -75,7 +75,7 @@ _MCF_thread_new_aligned(_MCF_thread_procedure* proc, size_t align, const void* d
 
         size_request = (uintptr_t) thrd->__data_opt + size - (uintptr_t) thrd;
         __MCF_ASSERT(size_need <= size_request);
-        HeapReAlloc(__MCF_crt_heap, HEAP_REALLOC_IN_PLACE_ONLY, thrd, size_request);
+        __MCF_mresize_0(thrd, size_request);
       }
 
       /* Copy user-defined data. If this doesn't happen, they are implicit zeroes.  */

mcfgthread/xglobals.h

@@ -232,6 +232,13 @@ __MCF_XGLOBALS_INLINE
 void*
 __MCF_malloc_0(size_t size) __attribute__((__malloc__, __alloc_size__(1)));
 
+/* Set the size a block of memory in place, like `truncate()` on files.
+ * If the existent block should be extended, vacuum bytes are filled with
+ * zeroes.  */
+__MCF_XGLOBALS_INLINE
+void*
+__MCF_mresize_0(void* ptr, size_t size) __attribute__((__alloc_size__(2)));
+
 /* Re-allocate a block of memory, like `realloc()`. If the existent
  * block should be extended, vacuum bytes are filled with zeroes.  */
 __MCF_XGLOBALS_INLINE
@@ -489,6 +496,13 @@ __MCF_malloc_0(size_t size)
     return HeapAlloc(__MCF_crt_heap, HEAP_ZERO_MEMORY, size);
   }
 
+__MCF_XGLOBALS_INLINE
+void*
+__MCF_mresize_0(void* ptr, size_t size)
+  {
+    return HeapReAlloc(__MCF_crt_heap, HEAP_ZERO_MEMORY | HEAP_REALLOC_IN_PLACE_ONLY, ptr, size);
+  }
+
 __MCF_XGLOBALS_INLINE
 void*
 __MCF_mrealloc_0(void** pptr, size_t size)