Change the order of a function in a file

Change to the same order as other files.
Merge branch 'master' into ruby-2.x

Conflicts:
	enc/utf_16le.c
cosmetic change
Change #ifndef scope

This change was made by Oniguruma 5.9.0, but it wasn't merged into Ruby
1.9.x or later.
Merge Ruby r17765 partly
Merge Ruby r30943

Show encoding of compiling regexp.
Merge branch 'master' into ruby-2.x