Hashes need to deoptimize based on their contents

[tenderlove]

If a hash has children that are not "basic" types of objects, then we can't consider the hash to be a static literal.

Fixes: #2015

I didn't see how to add tests for this, so I didn't. I think this is the fix, but I don't understand how to test.

[jemmaissroff]

To test, we'd usually make this change within ruby/ruby (src/prism.c maps to prism/prism.c over there), and add the tests to test/ruby/test_compile_prism.rb. If that all works, we'd merge this, and then merge the PR in ruby/ruby which tests it

[kddnewton]

This definitely looks right.

We need to expose these flags to Ruby/serialization in order to properly test it. But for now this mirrors what we do with arrays, so it makes sense to do it here.

[kddnewton]

Oh shoot sorry @jemmaissroff I wasn't paying attention and just saw your comment. I'm hoping that since the tests passed on CI here that everything should be fine.