* Add support for MALLOC_DEBUG and DEBUG_CHAOS to be used together.
* Add utils/astmm.c to .gitignore.
* Fix MALLOC_DEBUG variant of __ast_vasprintf. This function called
va_end(ap) upon allocation failure. This is incorrect since ap is
passed as an argument.
Change-Id: I9f27ced4ce3cbe4b39547a67f994fdff491978c0