* switch.adb (Is_Internal_GCC_Switch, Switch_Last): Bodies of ...
        * switch.ads (Is_Internal_GCC_Switch, Switch_Last): New functions.
        Add -auxbase variants to the list of recognized internal switches.
        * back_end.adb (Scan_Back_End_Switches): Use the new functions and
        adjust comments.
        * lib.ads: Make comment on internal GCC switches more general.
        * gcc-interface/lang-specs.h (specs for Ada): Pass -auxbase variants
        as for C.

From-SVN: r147830