The client program tests under src/bin use the Perl TAP tools and are run by prove. You can pass command-line options to prove by setting the make variable PROVE_FLAGS, for example:
make -C src/bin check PROVE_FLAGS='--reverse'
The default is --verbose. See the manual page of prove for more information.
The tests written in Perl require the Perl module IPC::Run. This module is available from CPAN or an operating system package. They also require PostgreSQL to be configured with the option --enable-tap-tests.