ensure __STDC_FORMAT_MACROS is always defined

C99 specifies that this macro must be defined if <inttypes.h> is to work
as expected in C++ environments.  Including <cinttypes> works around
this, but given that a number of places already include inttypes.h, we
might as well define the macro and be done.
fix some format directive mismatches
fix templated calls to std::max

With 64-bit ssize_t, the compiler complains about not being to match the
types of a bare `0' and an ssize_t.  Explicitly casting to ssize_t(0)
helps the compiler out.
handle missing SYS_socketcall in test/block.c
fix int-to-pointer cast with mismatched sizes
remove unnecessary static_assert in replay_syscall.cc

The static_assert claims that we need a specific function for writing a
uint32_t, but the templated Task::write_mem handles writing the uint32_t
just fine.
remove 32-bit assumptions around DBG_COMMAND_MAGIC_ADDRESS