file.c: rb_sys_fail_path_with_func

* file.c (rb_sys_fail_path_with_func): share same function, and path
  may be nil.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39760 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
internal.h: export rb_sys_fail_path_with_func

* internal.h (rb_sys_fail_path_with_func): export for
  socket/basicsocket.c.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39761 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Working id->symbol_entry, str->symbol_entry maps.
Merge branch 'symbol_entry' of github.com:kstephens/ruby into symbol_entry