importC int128 support timeline and other problem

[Dakota]

The problem list:


[importC Error: unsigned __int128 not 
supported](https://forum.dlang.org/post/gszrquconihrheekkxes@forum.dlang.org)

[importC error: _Builtin_stddef 
](https://forum.dlang.org/thread/gohvdcxmcgftglrmohjp@forum.dlang.org)


[inportC with postgres 16_4 on macOS 
error](https://forum.dlang.org/thread/lwndouyzgfojdpoxzyko@forum.dlang.org)


[no definition of struct 
`mach_vm_range](https://forum.dlang.org/post/tpebcqwzdqfkhnlkmbpd@forum.dlang.org)

[importC error: alignment value expected, not 
`sizeof`](https://forum.dlang.org/thread/yesaxwhyountswygbiua@forum.dlang.org)


[importC with struct name and function 
conflict](https://forum.dlang.org/thread/bmntorbovfaatfptukjp@forum.dlang.org)


the most important one is int128 support, I am not sure when it 
will be support or ever will be supported. or there will be 
workaround.


If it takes more than half a year, I will give up.