Bug 372182

+++ This bug was initially created as a clone of Bug #372120 +++

For the below code, the demanglers demangle a non c++ symbol as if it
would be a mangled c++ name.
This was detected on an Ada program (as gnat mangles Ada names by
replacing . by __) but that equally happens on c symbols having 2 underscores.
To reproduce:
gcc -g -o demang demang.c
./vg-in-place --leak-check=full ./demang
==30660== 90 bytes in 9 blocks are definitely lost in loss record 2 of 2
==30660==    at 0x4C27BB5: malloc (vg_replace_malloc.c:299)
==30660==    by 0x400515: main__calling__some(...)(long long,...)(char) (demang.c:7)
==30660==    by 0x40052C: main (demang.c:12)


#include <stdlib.h>
char *v;
void main__calling__some__exec(void)
{  
   int i;
   for (i = 0; i < 10; i++)
      v = malloc(10);
}

main ()
{
   main__calling__some__exec();
}