The following review has been posted through the commitfest application:
make installcheck-world: not tested
Implements feature: tested, passed
Spec compliant: tested, passed
Documentation: not tested
Patch does not apply cleanly on the master branch, anyways I managed that. Patch work according to specs, and no issue found.
The only minor nit is that you can keep the full comments of function strtoint64
/*
* If not errorOK, an error message is printed out.
* If errorOK is true, just return "false" for bad input.
*/