Added extra checks of 64-bit atomic support on GCC and Solaris, also added 64-bit support in solaris.h which was missing

According to new numbering scheme mysql-next-mr does not have
its own version. Some version placeholder is used instead.

It's been agreed that 5.5.99 will be used as a placeholder.

Fixed complex gcc assembler issues with 64-bit operations on 32-bit platforms using PIC codes, commented x86-gcc.h a lot more

Fixed an issue where STOP SLAVE generated a warning to error log which test case couldn't handle, fixed by checking for io slave killed before checking for network error

Conflicts:
  - extra/comp_err.c
  - mysql-test/collections/default.experimental
  - mysql-test/r/archive.result
  - mysql-test/r/select.result
  - mysql-test/suite/binlog/r/binlog_unsafe.result
  - mysql-test/suite/binlog/t/binlog_unsafe.test
  - mysql-test/suite/rpl/t/disabled.def
  - mysql-test/t/archive.test
  - mysql-test/t/select.test
  - sql/item.cc
  - sql/item.h
  - sql/item_timefunc.cc
  - sql/sql_base.cc
  - sql/sql_delete.cc
  - sql/sql_load.cc
  - sql/sql_partition.cc
  - sql/sql_table.cc
  - storage/innobase/handler/ha_innodb.cc
  - vio/vio.c

Conflicts:
  - client/mysqltest.cc
  - mysql-test/collections/default.experimental
  - mysql-test/suite/rpl/t/disabled.def
  - sql/mysqld.cc
  - sql/opt_range.cc
  - sql/sp.cc
  - sql/sql_acl.cc
  - sql/sql_partition.cc
  - sql/sql_table.cc

Part III: mysys instrumentation

WL#3951 - MyISAM: Additional Error Logs for Data Corruption
Fixed partition_repair_myisam.test.

Bug#35591 FLUSH PRIVILEGES caused a crash

A race condition on the privilege hash tables (proc_priv_hash
and func_priv_hash) caused one thread to try to delete elements
that had already been deleted by another thread.

The bug was caused by reading and saving the pointers to 
the hash tables outside mutex protection.  This led to an
inconsistency where a thread copied a pointer to a hash,
another thread did the same, the first thread then deleted
the hash, and the second then crashed when it in turn tried to
delete the deleted hash.

The fix is to ensure that operations on the shared hash structures
happens under mutex protection (moving the locking up a little)