Mainline build problems

[Aaron Gray]

There are problems with :-

        print-rtl.c:395
        c-common.c:4099
        c-pretty-print.c:822
        dwarf2asm.c:56
        dwarf2out.c:...

It seems to be a unsigned issue to do with HOST_WIDE_INT_PRINT_HEX, 
HOST_WIDE_INT_PRINT_DOUBLE_HEX and friends.

Aaron