RFA/patch stabs reader: Recognize language hint in SO stab

[Jason Molenda]

I knew I forgot something:  Testing.

I tested the patch on an x86 Linux box with gcc 3.4.0 with -gstabs+; 
there was no change with or without the patch.  The compiler wasn't 
setting the desc field in the SO stabs, of course, so I made a small 
C++ program

#include <iostream>

int foo (int a);
int
main()
{
    int a = 10;
    std::cout << "hi there" << a << std::endl;
    return foo (a);
}

int foo (int a)
{
   return a + 5;
}


called "a.c", and modified the stabs by hand to

         .file   "a.c"
         .stabs  "/tmp/",100,0,0,.Ltext0
         .stabs  "a.c",100,0,4,.Ltext0

The value 4 is N_SO_CC.  Without this change, this is what gdb looks 
like:

(gdb) b foo
Breakpoint 1 at 0x80488ed: file a.c, line 13.
(gdb) r
Starting program: /tmp/a.out
hi there10

Breakpoint 1, _Z3fooi (a=10) at a.c:14
14        return a + 5;
(gdb)


With this change, we get

(gdb) b foo
Breakpoint 1 at 0x80488ed: file a.c, line 14.
(gdb) r
Starting program: /tmp/a.out
hi there10

Breakpoint 1, foo (a=10) at a.c:14
14        return a + 5;
Current language:  auto; currently c++
(gdb)


Huzzah.

(obviously this is just an example of incorrect behavior -- when you're 
working with real C++ code the inability to detect the fact that it's a 
C++ program causes all sorts of problems.)

J