uninitialized variable used as subscript

Grouping select from a "constant" InnoDB table (a table
of a single row) joined with other tables caused a crash.

use same (slightly unwieldy) name in all trees; fix before this version goes "public".
bless ctype to avoid upmerge conflict, le sigh.

The problem is that when a optimization of read-only transactions
(bypass 2-phase commit) was implemented, it removed the code that
reseted the XID once a transaction wasn't active anymore:

sql/sql_parse.cc:

-  bzero(&thd->transaction.stmt, sizeof(thd->transaction.stmt));
-  if (!thd->active_transaction())
-    thd->transaction.xid_state.xid.null();
+  thd->transaction.stmt.reset();

This mostly worked fine as the transaction commit and rollback
functions (in handler.cc) reset the XID once the transaction is
ended. But those functions wouldn't reset the XID in case of
a empty transaction, leading to a assertion when a new starting
a new XA transaction.

The solution is to ensure that the XID state is reset when empty
transactions are ended (by either commit or rollback). This is
achieved by reorganizing the code so that the transaction cleanup
routine is invoked whenever a transaction is ended.

a binary distribution of the server as the MTR valgrind option
relies on it to silence unmeaningful warnings.

Implemented a way to circumvent the always true comparison by
having nested macros (as suggested on review).

Merged the 5.0 fix to 5.1 and fixed the 5.1 specific warnings.

Fixed the 5.0-bugteam MacOSX warnings.

 - Rename the  functions in mysqld that conflict with the one in the
   external interface defined by mysql.h

Holding on to the temporary inno hash index latch is an optimization in
many cases, but a pessimization in some others.

Release temporary latches for those corner cases we (or rather, or customers,
thanks!) have identified, that is, when we are about to do something that
might take a really long time, like REPAIR or filesort.

When copying the Item class one must copy its attributes as well.

Problem:
  Crash happened with a user-defined utf8 collation,
  on attempt to insert a value longer than the column
  to store.
Reason:
  The "ctype" member was not initialized (NULL) when
  allocating a user-defined utf8 collation, so an attempt
  to call my_ctype(cs, *str) to check if we loose any important
  data when truncating the value made the server crash.
Fix:
  Initializing tge "ctype" member to a proper value.


mysql-test/r/ctype_ldml.result
  Adding tests

mysql-test/t/ctype_ldml.test
  Adding tests

strings/ctype-uca.c
  Adding initialization of "ctype" member.

modified:
  mysql-test/r/ctype_ldml.result
  mysql-test/t/ctype_ldml.test
  strings/ctype-uca.c

The crash happens because of uninitialized
lex->ssl_cipher, lex->x509_subject, lex->x509_issuer variables.
The fix is to add initialization of these variables for
stored procedures&functions.

Let the user specify 'auto' for parallel value
Also set --parallel=auto in default.push so we can get this tested.