Development versions of cmocka require the intmax_t and uintmax_t types
to be defined by the time the test code includes the <cmocka.h> header.
These types are defined in the <stdint.h> header, which is included by
the <inttypes.h> header, which in turn is already explicitly included by
some of the programs in the tests/ directory. Ensure all programs in
that directory that include the <cmocka.h> header also include the
<inttypes.h> header to future-proof the code while keeping the change
set minimal and the resulting code consistent. Also prevent explicitly
including the <stdint.h> header in those programs as it is included by
the <inttypes.h> header.
when the branch implementing mutex_test was rebased and merged,
a rebasing error was missed: the isc_threadresult and isc_threadarg
types no longer exist.
Add simple mutex unit test and mutex benchmark. The benchmark compares
the pthread mutext with isc mutex implementation, so it's mainly useful
when developing a new isc mutex implementation.
