Third codegen test passing for simulated MIPS.

runtime/vm/runtime_entry_mips.cc

Index: runtime/vm/runtime_entry_mips.cc
===================================================================
--- runtime/vm/runtime_entry_mips.cc	(revision 20788)
+++ runtime/vm/runtime_entry_mips.cc	(working copy)
@@ -7,10 +7,41 @@
 
 #include "vm/runtime_entry.h"
 
+#include "vm/assembler.h"
+#include "vm/simulator.h"
+#include "vm/stub_code.h"
+
 namespace dart {
 
+#define __ assembler->
+
+
+// Generate code to call into the stub which will call the runtime
+// function. Input for the stub is as follows:
+//   SP : points to the arguments and return value array.
+//   S5 : address of the runtime function to call.
+//   S4 : number of arguments to the call.
 void RuntimeEntry::Call(Assembler* assembler) const {
-  UNIMPLEMENTED();
+  // Compute the effective address. When running under the simulator,
+  // this is a redirection address that forces the simulator to call
+  // into the runtime system.
+  uword entry = GetEntryPoint();
+#if defined(USING_SIMULATOR)
+  // Redirection to leaf runtime calls supports a maximum of 4 arguments passed
+  // in registers.
+  ASSERT(!is_leaf() || (argument_count() <= 4));
+  Simulator::CallKind call_kind =
+      is_leaf() ? Simulator::kLeafRuntimeCall : Simulator::kRuntimeCall;
+  entry = Simulator::RedirectExternalReference(entry, call_kind);
+#endif
+  if (is_leaf()) {
+    ExternalLabel label(name(), entry);
+    __ BranchLink(&label);
+  } else {
+    __ LoadImmediate(S5, entry);
+    __ LoadImmediate(S4, argument_count());
+    __ BranchLink(&StubCode::CallToRuntimeLabel());
+  }
 }
 
 }  // namespace dart