Wrong type of e1 << e2

[rillig]

https://stackoverflow.com/questions/55673029/does-a-c-shift-expression-have-unsigned-type

It's a bug in Splint. Splint wrongly assumes that the type of e1 << e2 is ctype_wider(te1, te2). The correct type would be just te1.

The buggy code starts here by using the same code path for the bitwise operators like &, | and ^, as well as for the << and >> operators.

The actual bug is at the end of that code, which assumes that for all these bitwise binary operators, the return type is ctype_wider(te1, te2).

[bpringlemeir]

Fixed by 5201227