Rewritten the following global utility constants:
`umax` returns max number, restricted to unsigned.
`smax` returns max signed number, restricted to integrals.
`smin` returns min signed number, restricted to signed.
`amin` returns smin or zero, less restricted.
`amax` returns smax or umax, less restricted.
Fix operators == and <=> for synthesized rel-ops.
- Multiple header files where missing #includes to other headers that
where used in the header. Correct header was included in correct
order in source files which caused everything to compile.
- Added missing #includes so header files correctly include all their
dependencies and fixes problems with IDEs being unable to parse
headers correctly due to missing symbols
Implement helper functions balanced_wait_until and balanced_awaken
They include new path for Windows 8.1+ (WaitOnAddress)
shared_mutex, cond_variable, cond_one, cond_x16 modified to use it
Added helper function utils::popcnt16
Replace most semaphore<> with shared_mutex