clang-14 is detected as being able to optimize out unreachable paths,
but then triggers a build error reporting an unspecified invalid use
somewhere in multi.cpp.
Remove the static check, and rely on -Wsuggest-attribute=noreturn to
report any functions which are guaranteed to fail. This is a weaker
check, but over the course of development, the static check has been hit
rarely, if ever, so keeping it provides little value.
```
In file included from similar/main/multi.cpp:38:
In file included from common/main/game.h:32:
In file included from common/main/robot.h:34:
In file included from common/main/object.h:40:
common/include/valptridx.h:229:2: error: call to unsigned int valptridx<dcx::player>::check_index_range_size<valptridx<dcx::player>::index_range_exception, std::__1::less>(char const*, unsigned int, unsigned long, valptridx<dcx::player>::array_managed_type const*)::DXX_ALWAYS_ERROR_FUNCTION::dxx_trap_handle_index_range_error() declared with 'error' attribute: invalid index used in array subscript
DXX_VALPTRIDX_CHECK(Compare<std::size_t>()(s, array_size), handle_index_range_error, "invalid index used in array subscript", a, s);
^
common/include/valptridx.h:37:3: note: expanded from macro 'DXX_VALPTRIDX_CHECK'
DXX_VALPTRIDX_STATIC_CHECK(dxx_valptridx_check_success_condition, dxx_trap_##ERROR, FAILURE_STRING); \
^
common/include/valptridx.h:20:5: note: expanded from macro 'DXX_VALPTRIDX_STATIC_CHECK'
(DXX_ALWAYS_ERROR_FUNCTION(FAILURE_FUNCTION, FAILURE_STRING), 0) \
^
build/ulinux-clang++-14-64b10d04-ogl/dxxsconf.h:84:2: note: expanded from macro 'DXX_ALWAYS_ERROR_FUNCTION'
DXX_ALWAYS_ERROR_FUNCTION::F(); \
^
1 error generated.
```