Export runtime version in Python3 runtime

[xrmx]

To make it easier for runtime user to choose a generated parser compatible for the runtime. Runtime 4.10 broke compatibility with parser compiled with 4.7.2 that were working till 4.9.X and so a way to have the version is handy if one want to support multiple runtime in the same codebase.

Signed-off-by: Riccardo Magliocchetti [email protected]

[KvanTTT]

It makes sense for an end user. But it should be fixed for all runtimes, not only Python.

[xrmx]

I can add the same for Python2 and javascript easily, i can try to hack something for the rest of the runtimes but it'll take a bit.

[lbisceglia]

Since you've moved the version to a different file, you'll have to update this as well: https://github.com/antlr/antlr4/blob/master/scripts/files-to-update.txt

[lbisceglia]

Created a PR for Golang support: https://github.com/antlr/antlr4/pull/3671

[parrt]

I think a lot of the runtimes already have the version information in the runtime metadata. E.g., https://github.com/antlr/antlr4/blob/master/runtime/Java/src/org/antlr/v4/runtime/RuntimeMetaData.java#L70