[tlbuild] Problems with parallel make

[Karl Berry]

Just to report back, Takuji and Hironori committed a fix (hopefully) for
the wcfname parallelization problem that Ken reported:
https://tug.org/svn/texlive?view=revision&revision=65831
(Run the tests in subdirs, so having the same name shouldn't be a problem.)

--thanks, karl.

P.S. Other recent statuses, just FYI:

- Martin has just committed changes to hitex. Hopefully they will
fly. He's now working on the delayed-expansion "\special shipout"
feature for hitex. (The tokens are expanded at \shipout time, like
a non-\immediate \write.)

- Phelype wrote the "\special shipout" implementation for the other
engines (luatex still in progress) and they are also committed.

- Thanh made a fix today for a beginbfrange CMap-related bug, which could
cause a pdftex-generated pdf not to validate when using, e.g., $\mu$.