Remove unused/not working function tracing flag and functionality.

runtime/vm/stub_code_ia32.cc

Index: runtime/vm/stub_code_ia32.cc
===================================================================
--- runtime/vm/stub_code_ia32.cc	(revision 14749)
+++ runtime/vm/stub_code_ia32.cc	(working copy)
@@ -2070,6 +2070,20 @@
 }
 
 
+// Calls to runtime to ooptimized give function
+// EDX: function to be reoptimized.
+// EAX: result of function being optimized (preserved).
+void StubCode::GenerateOptimizeFunctionStub(Assembler* assembler) {
+  AssemblerMacros::EnterStubFrame(assembler);
+  __ pushl(EAX);
+  __ pushl(EDX);
+  __ CallRuntime(kOptimizeInvokedFunctionRuntimeEntry);
+  __ popl(EDX);
+  __ popl(EAX);
+  __ LeaveFrame();
+  __ ret();
+}
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32