Adding JavaScript Preprocessor Support

[zlonast]

-optJSP was added to ghc similar to -optP for cpp.
I suggest supporting this change.
Implemented as discussed in #10722
Will close issue #10721

Template Α: This PR modifies behaviour or interface

• Patches conform to the coding conventions.
• Any changes that could be relevant to users have been recorded in the changelog.
  • Is the change significant? If so, remember to add significance: significant in the changelog file.
• The documentation has been updated, if necessary.
  Manual QA notes have been included.
• Tests have been added. (Ask for help if you don’t know how to write them! Ask for an exemption if tests are too complex for too little coverage!)

[angerman]

I'm confused about the JSP naming scheme.
We have CC: C compiler, and CPP, C pre-processor.
Now we have JSP? Java Server Pages? JavaScript Processor? JavaScript Pre?
I'd argue this should be jspp/JSPP. It's for a JavaScript Pre-Processor.

I think the naming in GHC with optP, and optJSP is rather poor, but we have cppOptions in cabal, so we don't need to replicate the poor naming here and could use jsppOptions.

[geekosaur]

Ping @GulinSS re ghc naming??

[GulinSS]

Hm, well, now I know why we use CPP and it is not a C++. 😄

Let's use anything what follow existing rules without copying jsp then. JSP was my first experience in GHC development participation and very probably I was not able to catch all details in one shot. Also I think that -optJSP is used rarely so we could try to schedule its renaming into a more appropriate variant.

[mpickering]

I noticed a few places which might need modifications. Looks like a good start, and thanks for the tests.

[zlonast]

I think now it looks the way I like it. The tests are written and are being passed :)

[zlonast]

@Mikolaj @Swordlash @phadej @angerman You might also be interested in this pull request 👀

[mpickering]

Looks good to me!

[Swordlash]

Wow, thanks for picking this up.