Moving similar code from sql_yacc.yy and sql_yacc_ora.yy to methods:
  LEX::maybe_start_compound_statement()
  LEX::sp_push_loop_label()
  LEX::sp_push_loop_empty_label()
  LEX::sp_pop_loop_label()
  LEX::sp_pop_loop_empty_label()

The EXIT statement will also reuse this code.