Thi is a backport from mysql-trunk to mysql-5.6; original
bzr revision id: marko.makela@oracle.com-20120828112616-pwnoijknfxudifa7

Declare all structs with a type name that ends in _t instead of _struct.

Replace all instances of

typedef struct foo_struct foo_t;

with forward declarations like this:

struct foo_struct;

Remove unnecessary forward declarations of structs.

The bulk conversion was performed by a Perl snippet:
perl -i -pe 's/_struct/_t/g;
s/^typedef struct\s+([a-zA-Z][a-zA-Z0-9_]*_t)\s+\1\;$/struct $1\;/g;' \
storage/innobase/*/*[ch]

After this, some manual adjustments were made, and the code was
grepped for 'typedef struct' and 'typedef enum'.

The patch itself was grepped for '^-.*"' to ensure that no strings
were changed (there is trx_lock_structs in the INFORMATION_SCHEMA
tables).

rb:1246 approved by Sunny Bains