plsql not support drop synonym

[shixiangwei]

plsql not support drop synonym

[shixiangwei]

g4 file can find create synonym, not drop synonym

    | create_index
    | create_table
    | create_tablespace
    | create_cluster
    | create_context
    | create_view //TODO
    | create_directory
    | create_materialized_view
    | create_materialized_view_log
    | create_user

    | create_sequence
    | create_trigger
    | create_type
    | create_synonym

    | drop_function
    | drop_package
    | drop_procedure
    | drop_sequence
    | drop_trigger
    | drop_type
    | data_manipulation_language_statements
    | truncate_table
    | drop_table
    | drop_view
    | drop_index