use uname -m to determine default MODEL
Fixes #11735. Enable printing unicode using pragma msg
Merge pull request #2959 from yazd/fix-11735

Issue 11735 - pragma(msg, ...) fails to print wstring, dstring
Merge pull request #2955 from MartinNowak/defaultMODEL

use uname -m to determine default MODEL
fix Issue 11730 - associative array with Nullable!SysTime values: Called `get' on null Nullable!SysTime

When I fixed bug 6178, I internally used `cast(void)exp)` to suppress unexpected "has no side effect" error.

But, `CastExp` always try to resolve alias this of its operand to find most matching type to `void` via `Expression::castTo`. It should be disabled.