common/dlmalloc.c: Delete content that was moved to malloc.h

Remove several hundred lines of content surrounded by:

#if 0  /* Moved to malloc.h */
... moved stuff ...
#endif /* 0 */                 /* Moved to malloc.h */

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Reviewed-by: Tom Rini <trini@konsulko.com>