Get rid of underscore.c

[Andrew Cagney]

> Which binutils change?  Removing c++filt from binutils?  I don't think it
> was discussed before the current thread, which is being sent to the
> binutils list.
> 
> I added c++filt to gcc on 1995-05-04.  I don't remember what discussion
> preceded this change.

Ah, ok.

>>> Why should binutils have its own demangler?
> 
>>
>> How about GCC bundle in a program called g++filt while binutils bundle
>> c++filt.
> 
> 
> I honestly don't see a reason for binutils to build c++filt.  Do you?  I'm
> not being sarcastic.

The demangler gets fixes and those fixes get pulled into GDB and 
BINUTILS.  Since (I believe) GDB and BINUTILS have more frequent 
releases than GCC, the user (we here are all developers so have a 
somewhat skewed view of the world) gets access to these updates more 
quickly.

I think of c++filt like addr2line and the other binutils as small 
utilities that give access to a mechanism that would otherwize only be 
available by running up GDB (outch).  I don't think someone should be 
required to download/build GCC to get access to that utility.

> If you really want to build it in binutils, I suppose we can work something
> out, just please don't remove it from gcc.

If it gets its own directory, both GCC and BINUTILS can package it.

Andrew