add an option --no-assert-failure-expression-printing

[zapashcanon]

Which would turn:

$ owi c file.c
Assert failure: (i32.ge symbol_0 (i32 0))
Model:
...

into:

$ owi c file.c --no-assert-failure-expression-printing
Assert failure!
Model:
...

It would help to make some CI tests passing, for instance test/c/eacsl/ghost/else.t.