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relocatable kernel support, bug #4224

Hi -

My final patch for this problem is now in CVS.  Please test it on some
recent kernels, for I'd like to refresh Fedora's systemtap with a
snapshot pronto.

The language change generated by this issue is summarized thusly in

- The numeric forms of kernel.statement() and kernel.function() probe points
  are now interpreted as relocatable values - treated as relative to the
  _stext symbol in that kernel binary.  Since some modern kernel images
  are relocated to a different virtual address at startup, such addresses
  may shift up or down when actually inserted into a running kernel.

     kernel.statement(0xdeadbeef): validated, interpreted relative to _stext,
                                   may map to 0xceadbeef at run time.

  In order to specify unrelocated addresses, use the new ".absolute"
  probe point suffix for such numeric addresses.  These are only
  allowed in guru mode, and provide access to no $target variables.
  They don't use debugging information at all, actually.

     kernel.statement(0xfeedface).absolute: raw, unvalidated, guru mode only

- FChE

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