Add remaining Information Functions

[morgo]

From the MySQL manual:

• BENCHMARK() Repeatedly execute an expression expression, planner: support builtin function benchmark #9252
• CHARSET() Return the character set of the argument Built-in function CHARSET not supported #3931
• COERCIBILITY() Return the collation coercibility value of the string argument Function coercibility not supported #4056
• COLLATION() Return the collation of the string argument
• CONNECTION_ID() Return the connection ID (thread ID) for the connection
• CURRENT_USER(), CURRENT_USER The authenticated user name and host name
• DATABASE() Return the default (current) database name
• FOUND_ROWS() For a SELECT with a LIMIT clause, the number of rows that would be returned were there no LIMIT clause (Exists, but not correctly implemented) inconsistent behavior of Found_Rows and sql_calc_found_rows #8235
• LAST_INSERT_ID() Value of the AUTOINCREMENT column for the last INSERT
• ROW_COUNT() The number of rows updated (Limited; hard to impliment in optimistic system)
• SCHEMA() Synonym for DATABASE()
• SESSION_USER() Synonym for USER()
• SYSTEM_USER() Synonym for USER()
• USER() The user name and host name provided by the client
• VERSION() Return a string that indicates the MySQL server version

[wwar]

COLLATION() and COERCIBILITY() can be checked as complete.

CHARSET() is still not done, and FOUND_ROWS() is still broken.

[ghost]

I am going to close this issue now. There are only two remaining functions, and both have dedicated issues to track them. Thanks!