tree-into-ssa.c (ssa_rewrite_initialize_block): Do not register definitions of SSA_NAMEs which are not being rewritten.

        * tree-into-ssa.c (ssa_rewrite_initialize_block): Do not register
        definitions of SSA_NAMEs which are not being rewritten.
        (rewrite_ssa_into_ssa): Only initialize the current definition
        of an SSA_NAME if that SSA_NAME has been marked for rewriting.
        If checking is enabled, assert that SSA_NAME_AUX is clear for all
        SSA_NAMEs before returning.

From-SVN: r94343