Autoload syntax error causes heap bug warning

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

torch% fpath=(/tmp/test $fpath)
torch% . /tmp/test/cause_bug
/tmp/test/cause_bug:3: parse error near `\n'
torch% autoload cause_bug
torch% compdef cause_bug foo
torch% foo <TAB>
cause_bug:3: parse error near `\n'
7: Src/mem.c:217: BUG: old_heaps() with pushed heaps

torch% cat /tmp/test/cause_bug
: deliberate sytax error:
while
torch%