[wasm] Fix I32ReinterpretF32 and I64ReinterpretF64 on ia32.

test/cctest/wasm/test-run-wasm-64.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "src/base/bits.h"
 #include "src/wasm/wasm-macro-gen.h"
@@ skipping 1276 matching lines @@
   BUILD(r, WASM_I64_REINTERPRET_F64(
                WASM_LOAD_MEM(MachineType::Float64(), WASM_ZERO)));
 
   FOR_INT32_INPUTS(i) {
     int64_t expected = static_cast<int64_t>(*i) * 0x300010001;
     r.module().WriteMemory(&memory[0], expected);
     CHECK_EQ(expected, r.Call());
   }
 }
 
+WASM_EXEC_TEST(SignallingNanSurvivesI64ReinterpretF64) {
+  REQUIRE(I64ReinterpretF64);
+  WasmRunner<int64_t> r(execution_mode);
+  BUILD(r, WASM_I64_REINTERPRET_F64(WASM_SEQ(kExprF64Const, 0x00, 0x00, 0x00,
+                                             0x00, 0x00, 0x00, 0xf4, 0x7f)));
+
+  // This is a signalling nan.
+  CHECK_EQ(0x7ff4000000000000, r.Call());
+}
+
 WASM_EXEC_TEST(F64ReinterpretI64) {
   REQUIRE(F64ReinterpretI64);
   WasmRunner<int64_t, int64_t> r(execution_mode);
   int64_t* memory = r.module().AddMemoryElems<int64_t>(8);
 
   BUILD(r, WASM_STORE_MEM(MachineType::Float64(), WASM_ZERO,
                           WASM_F64_REINTERPRET_I64(WASM_GET_LOCAL(0))),
         WASM_GET_LOCAL(0));
 
   FOR_INT32_INPUTS(i) {
@@ skipping 283 matching lines @@
         CHECK_EQ(expected, result);
       }
     }
   }
 }
 
 WASM_EXEC_TEST(MixedCall_i64_0) { Run_WasmMixedCall_N(execution_mode, 0); }
 WASM_EXEC_TEST(MixedCall_i64_1) { Run_WasmMixedCall_N(execution_mode, 1); }
 WASM_EXEC_TEST(MixedCall_i64_2) { Run_WasmMixedCall_N(execution_mode, 2); }
 WASM_EXEC_TEST(MixedCall_i64_3) { Run_WasmMixedCall_N(execution_mode, 3); }