1. For incomplete arrays with initializer list (`int x[] = {1};`) use the
initializer size as the array size.

2. For arrays initialized with a string literal translate it as an array
of character literals instead of `[*c]const u8`

3. Don't crash if an empty initializer is used for an incomplete array.

4. Add a test for multi-character character constants

Additionally lay some groundwork for supporting wide string literals.

fixes #4831 #7832 #7842