coerceToString, coerceToObject should be made consistent with ECMA standard

[jawline]

coerceToString should be rewritten to ToString,
coerceToObject should be rewritten ToObject,
etc for the informal model transformations

[tapaswenipathak]

Hi @jawline: Can I PR for the ticket? or is the ticket internal?

[jawline]

Feel free to take a look! in essence, I want to change coerceToObject, coerceToString, etc to ToBoolean, ToNumber, ToString and ToObject so that our function models can be more easily compared with the ECMA specification