debug subtract error

test/mjsunit/wasm/asm-wasm.js

 // 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.
 
 // Flags: --expose-wasm
 
 function assertWasm(expected, func, ffi) {
   print("Testing " + func.name + "...");
   assertEquals(expected, Wasm.instantiateModuleFromAsm(
       func.toString(), ffi).caller());
@@ skipping 1475 matching lines @@
       u0xffffffff: u0xffffffff,
       u0x80000000: u0x80000000,
       u0x87654321: u0x87654321,
     };
   }
   var wasm = Wasm.instantiateModuleFromAsm(asmModule.toString());
   assertEquals(0xffffffff, wasm.u0xffffffff());
   assertEquals(0x80000000, wasm.u0x80000000());
   assertEquals(0x87654321, wasm.u0x87654321());
 })();
+
+(function SubtractDebug() {
+  function asmModule() {
+    "use asm";
+    function main(x) {
+      x = x|0;
+      return (x - 0)|0;
+    }
+    return {main:main};
+  }
+  var wasm = Wasm.instantiateModuleFromAsm(asmModule.toString());
+  assertEquals(-1, wasm.main(-1));
+})();