fix Issue 8960 - Unable to set thread priority

- Ignore error when get-/setting the priority of a terminated thread.
Re-add forward declaration of _d_monitordelete
Fix extra case where goto skips initialization of variables
Merge pull request #965 from ibuclaw/fixgotoerror

Fix extra case where goto skips initialization of variables
Merge pull request #964 from ibuclaw/fixsepcomp

Re-add forward declaration of _d_monitordelete
Do not use sort property directly
Merge pull request #669 from yebblies/issue10318

Do not use sort property directly
add missing nothrow @nogc to signal functions
require nothrow for callWithStackShell callback
Don't use built-in array .sort in rt.util.container.treap
Merge pull request #970 from quickfur/adSort_1

Don't use built-in array .sort in rt.util.container.treap
Merge pull request #966 from MartinNowak/callWithStackShell

require nothrow for callWithStackShell callback
Merge pull request #550 from MartinNowak/fix8960

fix Issue 8960 - Unable to set thread priority