Bug#18396916 MAIN.OUTFILE_LOADDATA TEST FAILS ON ARM, AARCH64, PPC/PPC64
  
  The recorded results for the failing tests were wrong.
  They were introduced by the patch for
  Bug#30946 mysqldump silently ignores --default-character-set when used with --tab
  
  Correct results were returned for platforms where 'char' is implemented as unsigned.
  This was reported as 
  Bug#46895 Test "outfile_loaddata" fails (reproducible)
  Bug#11755168 46895: TEST "OUTFILE_LOADDATA" FAILS (REPRODUCIBLE)
  The patch for that bug fixed only parts of the problem,
  leaving the incorrect results in the .result file.
  
  Solution: use 'uchar' for field_terminator and line_terminator on all platforms.
  Also: remove some un-necessary casts, leaving the ones we actually need.