bc: Correct mis-merge of contrib/bc on upgrade to version 3.2.6
Revert "bc: Vendor import of Gavin Howard's bc version 3.2.6"
This reverts commit 601ac82194693fcae9d7d2a7ec7d66ebaf3fd61e.
Vendor import of Gavin Howard's bc version 3.2.6
(cherry picked from commit 47a52dc4d48f259ab7d9f9ba6b65f4f2331a22dc)
The files README.md and .gitignore had been lost and are restored
by this commit.
A lot of files used for fuzzing had been moved to a new place and
still existed in their previous location. Delete the now obsolete
files from the old location.
Approved by: re