[Bug jit/63854] Fix memory leaks seen in JIT

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63854

--- Comment #32 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Using:

RUN_UNDER_VALGRIND= \
  make check-jit \
    RUNTESTFLAGS="-v -v -v jit.exp=test-factorial.c"

trunk currently shows this:

LEAK SUMMARY:
   definitely lost: 55,908 bytes in 654 blocks
   indirectly lost: 107,842 bytes in 1,630 blocks
     possibly lost: 0 bytes in 0 blocks
   still reachable: 2,075,133 bytes in 686 blocks
        suppressed: 0 bytes in 0 blocks

so there are still some memory leaks.