This ticket will update the WiredTiger C coding standard to allow variables to be declared other than at the start of a function.

The work includes:

• updating the C coding standard wording
• updating compiler flags to
  • allow allow variables to be declared other than at the start of a function
  • ensure that any attempt to use a goto to jump over variable initialisation generates an error
• update code checkers (eg s_all) to support this change
• make a small number of example changes to the WiredTiger source code to demonstrate (and test) the coding standard change.