Rare fails of bibtex8 and/or bibtexu test

[Karl Berry]

    I face rare and random fails of tests/bibtex8.test and/or
    tests/bibtexu.test

Maybe it's a timing/parallelism/caching/something problem.
Are you running with make -j?

I see bibtex8.test and bibtexu.test are using the same input and output
filenames. I just changed bibtexu.test to change that (r66832). Hope
that helps.

    Should I increase string values of bibtex

No. These test bibs are tiny. --thanks, karl.