A cleanup for MDEV-17088 Provide tools to encode/decode mysql-encoded…

… file system names

- Load and convert the entire input file at once,
  rather than reading string-by-string using fgets().
  This change makes it possible to convert from UCS2, UTF16, UTF32 data.
- Adding the --delimiter command, to treat the specified
  characters as delimiters rather than data to convert.
  Useful in combination with `-f filename` or `-t filename`.
  The delimiter characters are not converted,
  they are copied from the input to the output as is.
- Adding diagnostics with line number and position if:
  * an illegal input byte sequence was found
  * a character cannot be converted to the target character set

client/CMakeLists.txt

@@ -80,7 +80,8 @@ MYSQL_ADD_EXECUTABLE(mysqlslap mysqlslap.c)
 SET_SOURCE_FILES_PROPERTIES(mysqlslap.c PROPERTIES COMPILE_FLAGS "-DTHREADS")
 TARGET_LINK_LIBRARIES(mysqlslap ${CLIENT_LIB})
 
-MYSQL_ADD_EXECUTABLE(mariadb-conv mariadb-conv.cc)
+MYSQL_ADD_EXECUTABLE(mariadb-conv mariadb-conv.cc
+                     ${CMAKE_SOURCE_DIR}/sql/sql_string.cc)
 TARGET_LINK_LIBRARIES(mariadb-conv mysys strings)
 
 # "WIN32" also covers 64 bit. "echo" is used in some files below "mysql-test/".