Failing t//tools/pbc_merge.t

[Chromatic]

Only one test file fails for me on Linux/PPC. I have the attached patch
applied locally to show off what seems odd. My output is:

$ perl -Ilib t/tools/pbc_merge.t
1..4
directory_pack segment 'MERGED_DB' used size 22 but reported 24
(Ret: 2142551472, Cursor: 270128576)

Parrot VM: Can't stat t/tools/pbc_merge_t1.pbc, code 2.
main: Packfile loading failed
not ok 1
# Failed test (t/tools/pbc_merge.t at line 71)
# got: ''
# expected: '42'
ok 2
directory_pack segment 'MERGED_DB' used size 34 but reported 32
(Ret: 2140818864, Cursor: 270134224)

Parrot VM: Can't stat t/tools/pbc_merge_t3.pbc, code 2.
main: Packfile loading failed
not ok 3
# Failed test (t/tools/pbc_merge.t at line 132)
# got: ''
# expected: 'Stirb nicht vor mir'
ok 4
# Looks like you failed 2 tests of 4.

Note that cursor and ret are much further away than 16 or 32 or even a couple
of hundred bytes. I don't really follow the code to debug it more though.

-- c