Mark entirely optimized out value as non-lazy.

Mark entirely optimized out value as non-lazy.

If a value is entirely optimized out, then there's nothing for
value_fetch_lazy to fetch.  Sequences like:

 if (value_lazy (retval))
   value_fetch_lazy (retval);

End up allocating the value contents buffer, wasting memory, for no
use.

gdb/ChangeLog
2013-11-26  Andrew Burgess  <aburgess@broadcom.com>

	* value.c (allocate_optimized_out_value): Mark value as non-lazy.