* function.c (retrofit_block): Abort if we don't find a suitable insn.
        (insert_block_after_note): Abort if we don't have a previous block.
        Remove FN parameter.
        * function.h: Adjust.

        * tree.c (walk_tree): Walk operand subtrees in forward order.
        * optimize.c (expand_call_inline): Likewise.
        (optimize_function): Initialize id->scope_stmt to something useful.
        (remap_block): Assume id->scope_stmt has a useful value.

From-SVN: r30965