Add --noopt flag that sets all kind of flags to make unoptimzied code as fast as possible (and not …

runtime/bin/main.cc

Index: runtime/bin/main.cc
===================================================================
--- runtime/bin/main.cc	(revision 45469)
+++ runtime/bin/main.cc	(working copy)
@@ -754,6 +754,8 @@
 "--enable-vm-service[:<port number>]\n"
 "  enables the VM service and listens on specified port for connections\n"
 "  (default port number is 8181)\n"
+"--noopt\n"
+"  run unoptimized code only\n"
 "\n"
 "The following options are only used for VM development and may\n"
 "be changed in any future version:\n");