try_catch.cc -> try-catch.cc

[Michael Elizabeth Chastain]

I actually thought about that.  :)  I believe this section applies:

  http://sources.redhat.com/gdb/onlinedocs/gdbint_16.html#SEC157
  The source language programs do @emph{not} need to be in a consistent
  style.  Since @value{GDBN} is used to debug programs written in many different
  styles, it's worth having a mix of styles in the testsuite; for
  instance, some @value{GDBN} bugs involving the display of source lines would
  never manifest themselves if the programs used GNU coding style
  uniformly.

I know it's unlikely that gdb will ever have a bug where it can't
handle '_' in a filename.  (Although gdb does have filename completion).
It's more the principle of keeping the test suite programs diverse
and uncanonicalized.

I'll change it if you want it changed, though.

Michael C