Corrected build issues : the build can not be conditional.
to keep a unique source .tar.gz distribution.


configure.in:
  Rolling back previous change
sql/Makefile.am:
  Partially rolling back previous change.
  The build has to be unconditional, for the source .tar.gz distribution
sql/mysql_priv.h:
  WL#3432 (Compile the Parser with a --debug --verbose option)
sql/sql_parse.cc:
  WL#3432 (Compile the Parser with a --debug --verbose option)
  
  Moved turn_parser_debug_on to sql_yacc.yy
sql/sql_yacc.yy:
  WL#3432 (Compile the Parser with a --debug --verbose option)
  
  Moved turn_parser_debug_on to sql_yacc.yy