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

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

Index: test/mjsunit/wasm/asm-wasm-f32.js
diff --git a/test/mjsunit/wasm/asm-wasm-f32.js b/test/mjsunit/wasm/asm-wasm-f32.js
index 66ef2747969a197db264851a7b12ed5981f4c64c..a1af7a43932c70530b4fc758fc84b100f764083d 100644
--- a/test/mjsunit/wasm/asm-wasm-f32.js
+++ b/test/mjsunit/wasm/asm-wasm-f32.js
@@ -41,13 +41,13 @@ function RunAsmJsTest(asmfunc, expect) {
   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);