port Bug#23150562 REMOVE UNIV_MUST_NOT_INLINE AND UNIV_NONINL

Also, remove empty .ic files that were not removed by my MySQL commit.

Problem:

InnoDB used to support a compilation mode that allowed to choose whether the function definitions in .ic files are to be inlined or not. This stopped making sense when InnoDB moved to C++ in MySQL 5.6 (and ha_innodb.cc started to #include .ic files), and more so in MySQL 5.7 when inline methods and functions were introduced in .h files.

Solution:

Remove all references to UNIV_NONINL and UNIV_MUST_NOT_INLINE from all files, assuming that the symbols are never defined. Remove the files fut0fut.cc and ut0byte.cc which only mattered when UNIV_NONINL was defined.