add option --T_dont_fork to tracee (lte-softmodem, oaisim)

The T has 2 processes: the tracee and the local tracer
if the tracee dies (segfault or whatever) the tracee
may still be running.

So there is a third process that monitors those two others
and kill everything when one dies.

The problem is that this third process has to be the parent
of the two others. That makes debugging the tracee with gdb
impossible. This new option disables the third monitor process.

targets/SIMU/USER/oaisim.c

@@ -250,6 +250,7 @@ help (void)
 #if T_TRACER
   printf ("--T_port [port]    use given port\n");
   printf ("--T_nowait         don't wait for tracer, start immediately\n");
+  printf ("--T_dont_fork      to ease debugging with gdb\n");
 #endif
 }
 
@@ -1258,6 +1259,7 @@ l2l1_task (void *args_p)
 #if T_TRACER
 int T_wait = 1;       /* by default we wait for the tracer */
 int T_port = 2021;    /* default port to listen to to wait for the tracer */
+int T_dont_fork = 0;  /* default is to fork, see 'T_init' to understand */
 #endif
 
 /*------------------------------------------------------------------------------*/
@@ -1294,7 +1296,7 @@ main (int argc, char **argv)
   get_simulation_options (argc, argv); //Command-line options
 
 #if T_TRACER
-  T_init(T_port, T_wait);
+  T_init(T_port, T_wait, T_dont_fork);
 #endif
 
   // Initialize VCD LOG module

targets/SIMU/USER/oaisim_functions.c

@@ -216,6 +216,7 @@ void get_simulation_options(int argc, char *argv[])
 #if T_TRACER
     LONG_OPTION_T_PORT,
     LONG_OPTION_T_NOWAIT,
+    LONG_OPTION_T_DONT_FORK,
 #endif
   };
 
@@ -254,6 +255,7 @@ void get_simulation_options(int argc, char *argv[])
 #if T_TRACER
     {"T_port",                 required_argument, 0, LONG_OPTION_T_PORT},
     {"T_nowait",               no_argument,       0, LONG_OPTION_T_NOWAIT},
+    {"T_dont_fork",            no_argument,       0, LONG_OPTION_T_DONT_FORK},
 #endif
 
     {NULL, 0, NULL, 0}
@@ -436,6 +438,12 @@ void get_simulation_options(int argc, char *argv[])
       T_wait = 0;
       break;
     }
+
+    case LONG_OPTION_T_DONT_FORK: {
+      extern int T_dont_fork;
+      T_dont_fork = 1;
+      break;
+    }
 #endif
 
     case 'a':