basic-block.h (basic_block_head): Rename to x_basic_block_head.

basic-block.h (basic_block_head): Rename to x_basic_block_head.

        * basic-block.h (basic_block_head): Rename to x_basic_block_head.
        (basic_block_end): Rename to x_basic_block_end.
        (BLOCK_HEAD, BLOCK_END): Update.
        * caller-save.c: Change basic_block_head/end references to
        BLOCK_HEAD/END.
        * combine.c, flow.c, function.c, gcse.c, global.c: Likewise.
        * graph.c, haifa-sched.c, local-alloc.c, regclass.c: Likewise.
        * regmove.c, reload1.c, reorg.c, sched.c: Likewise.

From-SVN: r24622