Modularize sign, ceil, floor, neg

[tafsiri]

Modularize sign, ceil, floor, neg.

Also improves tooling for speeding up modularization:

• scripts/extract_op.ts will move ops from one file into their own file, and handle updating the old file as well as exports in ops.ts
• scripts/touch_modular_ops_files.ts emits a more complete kernel template and also supports generating files for multiple ops and kernels in one call.

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[annxingyuan]

awesome! just curious - did you use the scripts you added to modularize sign / ceil / floor / neg? :)

[tafsiri]

@annxingyuan yep, if def helped speed it up. I also saw noticed that it is useful to make local modifications to templates when necessary, for example the gradient of the unary ops have a particular shared pattern, so as i do the rest i'll adapt the template to that pattern (but not commit that change).