Replace call to value_contents_raw by call to value_contents.

Replace call to value_contents_raw by call to value_contents.

This is something that Tom spotted.  It shouldn't make much of a difference
in practice with the current code, but Tom is planning on making some
changes (bitwise optimized-out tracking) in value_contents...

2010-05-27  Joel Brobecker  <brobecker@adacore.com>

        * ada-lang.c (ensure_lval): Replace call to value_contents_raw
        by call to value_contents.