VM: Avoid running atexit() handlers during exit() of a failed subprocess spawn

runtime/bin/process_linux.cc

Index: runtime/bin/process_linux.cc
diff --git a/runtime/bin/process_linux.cc b/runtime/bin/process_linux.cc
index 41978693acc33036a8e1899db3d8d578cc1ab1af..ae686e5c66bb638382c6ef11071ee4a4f62ab7f5 100644
--- a/runtime/bin/process_linux.cc
+++ b/runtime/bin/process_linux.cc
@@ -682,7 +682,10 @@ class ProcessStarter {
                                strlen(os_error_message) + 1);
     }
     VOID_TEMP_FAILURE_RETRY(close(exec_control_[1]));
-    exit(1);
+
+    // We avoid running through registered atexit() handlers because that is
+    // unnecessary work.
+    _exit(1);
   }