MIPS: Fix several bugs that cause crashes in soft-float mode.

src/mips/simulator-mips.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1484 matching lines @@
           case ExternalReference::BUILTIN_FP_INT_CALL:
             GetFpArgs(&dval0, &ival);
             PrintF("Call to host function at %p with args %f, %d",
                 FUNCTION_ADDR(target), dval0, ival);
             break;
           default:
             UNREACHABLE();
             break;
         }
       }
-      double result = target(arg0, arg1, arg2, arg3);
       if (redirection->type() != ExternalReference::BUILTIN_COMPARE_CALL) {
-          SetFpResult(result);
+        SimulatorRuntimeFPCall target =
+            reinterpret_cast<SimulatorRuntimeFPCall>(external);
+        double result = target(arg0, arg1, arg2, arg3);
+        SetFpResult(result);
       } else {
+        SimulatorRuntimeCall target =
+            reinterpret_cast<SimulatorRuntimeCall>(external);
+        uint64_t result = target(arg0, arg1, arg2, arg3, arg4, arg5);
         int32_t gpreg_pair[2];
         memcpy(&gpreg_pair[0], &result, 2 * sizeof(int32_t));
         set_register(v0, gpreg_pair[0]);
         set_register(v1, gpreg_pair[1]);
       }
     } else if (redirection->type() == ExternalReference::DIRECT_API_CALL) {
       // See DirectCEntryStub::GenerateCall for explanation of register usage.
       SimulatorRuntimeDirectApiCall target =
                   reinterpret_cast<SimulatorRuntimeDirectApiCall>(external);
       if (::v8::internal::FLAG_trace_sim) {
@@ skipping 1308 matching lines @@
 }
 
 
 #undef UNSUPPORTED
 
 } }  // namespace v8::internal
 
 #endif  // USE_SIMULATOR
 
 #endif  // V8_TARGET_ARCH_MIPS