Support for `rules` in ninja

[indutny]

We probably need to support targetDict.rules in ninja generator:

https://github.com/nodejs/node/blob/f782824d4829d89b078aafcdcc3a1fa043b58f39/deps/openssl/masm_compile.gypi#L4-L22

[indutny]

https://gyp.gsrc.io/docs/LanguageSpecification.md#Rules

[indutny]

I think we may probably skip it for now:

nodejs/node#7426