[wasm] Avoid using const that triggers ignition and flakes on ARM.

test/mjsunit/wasm/asm-wasm-f32.js

 // Copyright 2016 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: --validate-asm --allow-natives-syntax
 
 function WrapInAsmModule(func) {
   function MODULE_NAME(stdlib) {
     "use asm";
     var fround = stdlib.Math.fround;
@@ skipping 23 matching lines @@
   print("Testing " + asmfunc.name + " (js)...");
   var js_module = eval("(" + nonasm_source + ")")(stdlib);
   expect(js_module);
 
   print("Testing " + asmfunc.name + " (asm.js)...");
   var asm_module = asmfunc(stdlib);
   assertTrue(%IsAsmWasmCode(asmfunc));
   expect(asm_module);
 }
 
-const fround = Math.fround;
-const Math_ceil = Math.ceil;
-const Math_floor = Math.floor;
-const Math_sqrt = Math.sqrt;
-const Math_abs = Math.abs;
-const Math_min = Math.min;
-const Math_max = Math.max;
+var fround = Math.fround;
+var Math_ceil = Math.ceil;
+var Math_floor = Math.floor;
+var Math_sqrt = Math.sqrt;
+var Math_abs = Math.abs;
+var Math_min = Math.min;
+var Math_max = Math.max;
 
 function f32_add(a, b) {
   a = fround(a);
   b = fround(b);
   return fround(fround(a) + fround(b));
 }
 
 function f32_sub(a, b) {
   a = fround(a);
   b = fround(b);
@@ skipping 175 matching lines @@
             assertEquals(func(a / 11,  b), module.main(a / 11, b));
             assertEquals(func(a, b / 420.9), module.main(a, b / 420.9));
             assertEquals(func(a / -31.1, b), module.main(a / -31.1, b));
           }
         }
       }
     });
   }
 
 })();