Move TLB faults into the normal Fault code. The TLB no longer fills in IPRs through...

Move TLB faults into the normal Fault code.  The TLB no longer fills in IPRs through its own fault() method; this is handled by the fault's invoke() methods.

arch/alpha/faults.cc:
    Move TLB fault code into the normal fault invoke() method.
arch/alpha/faults.hh:
    Move DTB/ITB fault handling code into their own class with a specific invoke() method.  Have DTB/ITB faults derive from these classes.

    Unfortunately the DtbAlignmentFault is somewhat odd; it's a normal alignment fault, but it must also set some specific IPRs.
arch/alpha/tlb.cc:
arch/alpha/tlb.hh:
    Setting IPRs is now handled through the fault itself.

--HG--
extra : convert_revision : 5cb92ce2186ff79f632bfcbc9ba62a8a04400eae