Waveglow ONNX->TRT conversion, TRT working now
This pull request **introduces 1 alert** when merging 2b77dfcca2b19881218f87bc99f1f1c85fa98c3a into 8a26496f415386f50adcead21ebd1e4a21a7ff42 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-9556f0d6937d4abed6bef1a6fcdbb5f88bbac784)

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* 1 for Unreachable code This pull request **introduces 2 alerts** when merging 27f927afa4a746327b56cec94ce88fd7b18ae029 into 14904fd0381f5515a9773cf7a538dc09e08c8aa9 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-8702108d32f4503a8cddd6f1721d20aa4f324f5d)

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* 1 for Unreachable code This pull request **introduces 2 alerts** when merging 9947384cbfecf8aa5a8ced38ee5cde6787c23673 into 14904fd0381f5515a9773cf7a538dc09e08c8aa9 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-fed24cd035aca1a748126aa41339fea21c685da5)

**new alerts:**

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**new alerts:**

* 1 for Unused local variable This pull request **introduces 1 alert** when merging ff79d88df2af44d5cfd0c9f76819ec29e5d4d561 into 14904fd0381f5515a9773cf7a538dc09e08c8aa9 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-38ee321f3313035825dba3ec32c03f47a7b401c1)

**new alerts:**

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**new alerts:**

* 1 for Unused local variable This pull request **introduces 1 alert** when merging b4924c00ff7a7c778468851191f6ff8ca05cb2d8 into 14904fd0381f5515a9773cf7a538dc09e08c8aa9 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-6a52cec5dd2875eaf43026862ce672f5645839cc)

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 I can build TRT from ONNX now after 1D->2D conversion. Please pull from the last branch.
To get the real ONNX built, run test_waveglow.py (without pytest), after uncommenting this line:

model = WaveGlowModel.restore_from(“../WaveGlow-22050Hz-268M.nemo”) 
(place .nemo accordingly).  
There is also sample TRT build routine there - but whatever you used before should work as well.
This PR does contain a number of cleanups, plumbing and fixes.