Visit the current buffer's file again using coding system CODING-SYSTEM.
For a list of possible values of CODING-SYSTEM, use M-x list-coding-systems.
If CODING-SYSTEM leaves the text conversion unspecified, or if it leaves
the end-of-line conversion unspecified, FORCE controls what to do.
If FORCE is nil, get the unspecified aspect (or aspects) from the buffer's
previous `buffer-file-coding-system' value (if it is specified there).
Otherwise, determine it from the file contents as usual for visiting a file.