A DWARF-2 debug_line Reader in Java

This is an interpreter for the byte codes of the .debug_line sections
in DWARF-2 debug info. All boring details aside, what the .debug_line
byte codes are for is mapping program counter addresses to source file
names and line numbers. So if you have a stack trace of program
counter values, you can look up what statements in the original
program they correspond to. Debuggers like GDB read this section when
telling you where your program crashed.

This code, that I wrote, reads this information out of binary files
(currently, 32-bit ELF is supported, but extending it should not be
difficult).

I originally intended for this to be a part of GCJ, and it would
support generating exception stack traces, by filling in the source
file and line number, instead of the current method, which forks off
an external process to read this information. The patch wasn't
accepted into GCJ, and I'm not entirely sure why.

But the code still exists, and may be interesting to others who are
trying to develop GCJ-compiled code, or those who are merely curious
about things like ELF and DWARF-2.