[libc++abi] Reword uncaught exception termination message

[ldionne]

Summary

When we terminate due to an exception being uncaught, libc++abi prints
a message saying "terminating with uncaught exception [...]". This patch
changes that to say "terminating due to uncaught exception [...]" instead,
which is a bit clearer. Indeed, I've seen some people being confused and
thinking that libc++abi was the component throwing the exception.

[ldionne]

CI failures are just flake, ignoring them.

libcxxabi/src/cxa_default_handlers.cpp

 #endif
                 // If the uncaught exception can be caught with std::exception&
                 const __shim_type_info* catch_type =
                     static_cast<const __shim_type_info*>(&typeid(std::exception));
                 if (catch_type->can_catch(thrown_type, thrown_object))
                 {
                     // Include the what() message from the exception
                     const std::exception* e = static_cast<const std::exception*>(thrown_object);
-                    abort_message("terminating with %s exception of type %s: %s",
+                    abort_message("terminating due to %s exception of type %s: %s",
                                   cause, name, e->what());
                 }
                 else
-                    // Else just note that we're terminating with an exception
-                    abort_message("terminating with %s exception of type %s",
+                    // Else just note that we're terminating due to an exception
+                    abort_message("terminating due to %s exception of type %s",
                                    cause, name);
             }
             else
-                // Else we're terminating with a foreign exception
-                abort_message("terminating with %s foreign exception", cause);
+                // Else we're terminating due to a foreign exception
+                abort_message("terminating due to %s foreign exception", cause);
         }
     }
 #endif
     // Else just note that we're terminating
     abort_message("terminating");
 }
 
 __attribute__((noreturn))