Bug#926134: antlr4: Please package Python 3 runtime

[Benjamin Barenblat]

Source: antlr4
Version: 4.7.2-1

Coq now needs the ANTLR 4 runtime for Python 3 to generate its HTML
documentation. Would you be willing to add it to the antlr4 package?

This may be a duplicate of https://bugs.debian.org/897129, but lacking
familiarity with ANTLR, it’s not clear to me whether that bug is asking
for the runtime or for bindings to script against ANTLR.