Adjusted the pointer in error messages for infix operators that miss the right-side operand.
Adjusted the pointer in error messages for infix operators that miss the right-side operand.

Example:

	1 + 2 +

Fails with message:

File : y.sf
Line : 6 : 6
Error: operator `+` requires a right-side operand

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 + 2 +
      ^
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

trizen/sidef,trizen/sidef,trizen/sidef,trizen/sidef