[kenlm] New Port

[jacobkahn]

Adds a port for the the KenLM library.

Things to note:

• KenLM doesn't support a CMake install target, so files are manually globbed as needed.
• KenLM appears to only build static libs.
• The KenLM repo doesn't have tags, so I've used the current commit on top of master.
• Adds bin tools as built by the library.

Which triplets are supported/not supported? Have you updated the CI baseline?

Tested x64-linux.

Does your PR follow the maintainer guide?

Yes.

cc @kpu

[ghost]

All CLA requirements met.

[JackBoosY]

• KenLM doesn't support a CMake install target, so files are manually globbed as needed.

We need to patch it's cmake files.

[JackBoosY]

Please make sure the headers are all installed.

[kpu]

Hi! You're welcome to drive by and patch my cmake.

[jacobkahn]

@JackBoosY @kpu thanks very much for both of your time working on this — where do we stand now? It looks like Port CI is failing on Linux...

[kpu]

The linux build is failing on https://dev.azure.com/vcpkg/public/_build/results?buildId=43506&view=logs&j=d3670d0c-cc82-50c9-762c-eccde036829f&t=b5ba9409-7383-59d6-95ee-7a65895d5946&l=2182 complaining it is missing streaming_example from the interpolation code. This works in master...

[kpu]

I think the only patch you still need is IF( WIN32 AND BUILD_SHARED_LIBS) which I wouldn't do because it broke continuous integration on windows.

[JackBoosY]

I'm OOF now, will continue this PR when I return.

[JackBoosY]

@kpu Tool streaming_example is gone in *inx ?

[kpu]

streaming_example is more documentation about how to use the code as a library, compiled to check that it still works, rather than an actually useful executable worth installing.

[JackBoosY]

@kpu, fine. So I'm done. Do you have any suggestions about this PR?

[jacobkahn]

Gentle bump, cc @kpu — are we ok to merge?

[jacobkahn]

@JackBoosY — are we ok to merge this? I think we need an accept from you.

[JackBoosY]

@BillyONeal Ping for merge this PR.

[BillyONeal]

Thanks for your contribution!