Clean up oop.hpp: add inline directives and fix header files

This change moves inline directives from oop.inline.hpp to oop.hpp.
It sorts methods in oop.inline.hpp as they are sorted in oop.hpp.

Also, calls to methods implemented in oop.inline.hpp are removed from header files. A row of inline directives are skipped for now as they need fixes in gc coding, see 8146395.