Hi,

This patch implements some unary operations for GNU vectors.
The following operators have been verified:
- pre/post increment (++)
- pre/post decrement (--)
- unary plus (+)
- unary minus (-)
- bitwise not/complement (~)

It also prevents GDB from returning a lvalue in case of post 
increment/decrement.
Tested on i686-*-linux-gnu, no regressions.

Regards
Ken Werner