PATCH RFA: C++ frontend: Don't warn about shifts which will not be run

[Jason Merrill]

On 06/12/2009 09:01 PM, Ian Lance Taylor wrote:
> Suppose we eliminate skip_evaluation from the C and C++ frontends, since
> it seems to be poorly named, and replace it with "c_parsing_sizeof_arg"
> (which would also apply to typeof and alignof; better names solicited)
> and "c_never_executed".

This makes sense to me.  For the former, the C++ standard term is 
"unevaluated operand".  I'd rather not use the word "parsing" since we 
look into these expressions during template substitution as well.

Jason