[CVS ci] PackFile-15: print warning location

[Leopold Toetsch]

The debug segment (generated with -w or -d commandline options) has 
source file name and line number information.
When now parrot is run with the slow core and warnings are enabled, the 
location of the warnings is printed.

$ parrot -bw h.pasm #[1]
Use of uninitialized value in string context at h.pasm line 7.
Use of uninitialized value in string context at h.pasm line 10.
Question is: Should -w automatically select the slow core?
(This is currently the only core which tracks interpreter->cur_pc)
Further:
The C<setline> and C<setfile> opcodes are suboptimal, they impose 
runtime penalty on each run core, so they will go finally. The 
C<getline> and C<getfile> can map to the functionality used in warnings.c.

And finally: Parrot will (again[2]) track HLL source line info like:

  #line 17 "sourcefile.p6"

So that warnings and errors can be located in HLL source too.

Have fun
leo
[1]
$ cat h.pasm
  new P1, .PerlHash
  # new P3, .PerlString
  # set P3, "yyy\n"
  # set P1["a"], P3
  set P0, P1["a"]
  print P0
  set P0, "xxx\n"
  set P2, P1["a"]
  print P2
  end
[2] IIRC was that one of my first patches to imcc.