pre-allocate file size before write

src/os/core/win32/os_core_win32.c

@@ -494,6 +494,19 @@ os_rename_file_by_handle(OS_Handle file, String8 new_name)
   return is_renamed;
 }
 
+internal B32
+os_file_reserve_size(OS_Handle file, U64 size)
+{
+  HANDLE handle = (HANDLE)file.u64[0];
+
+  FILE_ALLOCATION_INFO alloc_info    = {0};
+  alloc_info.AllocationSize.LowPart  = size & max_U32;
+  alloc_info.AllocationSize.HighPart = (size >> 32) & max_U32;
+
+  BOOL is_reserved = SetFileInformationByHandle(handle, FileAllocationInfo, &alloc_info, sizeof(alloc_info));
+  return is_reserved;
+}
+
 internal B32
 os_delete_file_at_path(String8 path)
 {