include paths from dwfl

[Andrew Cagney <cagney@redhat.com>]

Rick,

This is from the dwarf3 spec:

10. include_directories (sequence of path names)
    The sequence contains an entry for each path that was searched for 
included source files in
    this compilation. (The paths include those directories specified 
explicitly by the user for the
    compiler to search and those the compiler searches without explicit 
direction). Each path
    entry is either a full path name or is relative to the current 
directory of the compilation. The
    current directory of the compilation is understood to be the first 
entry and is not explicitly
    represented. Each entry is a null-terminated string containing a 
full path name. The last entry
    is followed by a single null byte.


the address of the first path, aka the compilation directory, is 
obtained by lib.dw.DwflLine.getCompilationDirectory (see the cni code 
for the exact method).  The other paths just follow it, with an extra 
NIL terminator.

I think an extra cni method that returns either a List or File[] of 
File, created by scanning the C-strings, would give what is needed.

Andrew