Fix unsigned multiplication in MIPS simulator (add assembler regression test).

runtime/vm/assembler_mips_test.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/os.h"
@@ skipping 487 matching lines @@
 }
 
 
 ASSEMBLER_TEST_RUN(Multu_lo, test) {
   typedef int (*SimpleCode)() DART_UNUSED;
   EXPECT_EQ(42, EXECUTE_TEST_CODE_INT32(SimpleCode, test->entry()));
 }
 
 
 ASSEMBLER_TEST_GENERATE(Multu_hi, assembler) {
-  __ LoadImmediate(T1, 65536);
-  __ LoadImmediate(T2, 65536);
+  __ LoadImmediate(T1, -1);
+  __ LoadImmediate(T2, -1);
   __ multu(T1, T2);
   __ mfhi(V0);
   __ jr(RA);
 }
 
 
 ASSEMBLER_TEST_RUN(Multu_hi, test) {
   typedef int (*SimpleCode)() DART_UNUSED;
-  EXPECT_EQ(1, EXECUTE_TEST_CODE_INT32(SimpleCode, test->entry()));
+  EXPECT_EQ(0xfffffffe, EXECUTE_TEST_CODE_INT32(SimpleCode, test->entry()));
 }
 
 
 ASSEMBLER_TEST_GENERATE(Madd_neg, assembler) {
   __ LoadImmediate(T1, -6);
   __ LoadImmediate(T2, 7);
   __ mult(T1, T2);
   __ madd(T1, T2);
   __ mflo(V0);
   __ mfhi(V1);
@@ skipping 1533 matching lines @@
                      A1);
   __ lw(RA, Address(SP, 0 * kWordSize));
   __ lw(CTX, Address(SP, 1 * kWordSize));
   __ addiu(SP, SP, Immediate(2 * kWordSize));
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS