Remove unused flag --print-cfg.

Review URL: http://codereview.chromium.org/257030

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3007 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/flag-definitions.h

@@ -270,7 +270,6 @@ DEFINE_string(stop_at, "", "function name where to insert a breakpoint")
 // compiler.cc
 DEFINE_bool(print_builtin_scopes, false, "print scopes for builtins")
 DEFINE_bool(print_scopes, false, "print scopes")
-DEFINE_bool(print_cfg, false, "print control-flow graph")
 
 // contexts.cc
 DEFINE_bool(trace_contexts, false, "trace contexts operations")