Fix bug 10989 [CTFE] Uncaught exception messages are not pretty printed

Convert it to a StringExp before printing.
Fix issue 10994 CTFE void-initialized static arrays
Merge pull request #2562 from donc/regression10994void

10994 CTFE cannot declare statics with void-initialized static arrays
Merge pull request #2563 from donc/uncaught10989

10989 [CTFE] Uncaught exception messages are not pretty printed