Fix the Mac debugger attachment on segfault

[jdeans289]

Currently, code to attach a debugger and dump a stack trace is failing on Mac. This has been useful in the past, but now is hanging and crashing terminals on Mac, so it has been removed. Investigate this issue and try to restore the stack trace on segfault.

This issue can be closed when:

1. Stack traces can be dumped on Macs without hanging the terminal
2. A test is written verifying this behavior (possibly, might be difficult since it would involve a segfault and using debuggers in github CI, but an attempt should be made

• OR -

1. It is determined that this is no longer possible or not fixable with a reasonable amount of work.

[jmpenn]

The problematic code referred-to (above) was removed from trick_source/sim_services/Executive/Executive_signal_handler.cpp
in commit 1cf4ef5 , associated with issue #1383.

72 #elif __APPLE__
73          char command[2048];
74          char path[1024] ;
75          uint32_t size = sizeof(path) ;
76          if (_NSGetExecutablePath(path, &size) == 0 ) {
77              if (attach_debugger == true) {
78                  write( 2 , "Attempting to attach debugger... standby.\n" , 41 ) ;
79                  sprintf(command, "%s -silent %s %d", debugger_command.c_str(), path, getpid());
80                  system(command);
81              } else if (stack_trace == true ) {
82                  write( 2 , "Attempting to generate stack trace... standby.\n" , 47 ) ;
83                  sprintf(command, "%s -batch -s ${TRICK_HOME}/share/trick/lldb_commands -p %d",
84                   debugger_command.c_str(), getpid());
85                 system(command);
86              }
87          }

[jmpenn]

The debugger_command string is set in Trick::Executive::Executive(), in Executive.cpp.

24    struct stat st ;
25    if ( stat("/usr/bin/gdb",&st) == 0 ) {
26        debugger_command = std::string("/usr/bin/gdb") ;
27    } else if ( stat("/usr/bin/lldb",&st) == 0 ) {
28        debugger_command = std::string("/usr/bin/lldb") ;
29    }