jscript: Added Math.abs with no arg implementation.

dlls/jscript/math.c

@@ -121,8 +121,9 @@ static HRESULT Math_abs(DispatchEx *dispex, LCID lcid, WORD flags, DISPPARAMS *d
     TRACE("\n");
 
     if(!arg_cnt(dp)) {
-        FIXME("arg_cnt = 0\n");
-        return E_NOTIMPL;
+        if(retv)
+            num_set_nan(retv);
+        return S_OK;
     }
 
     hres = to_number(dispex->ctx, get_arg(dp, 0), ei, &v);

dlls/jscript/tests/api.js

@@ -431,6 +431,15 @@ ok(tmp === 3, "Math.abs(-3) = " + tmp);
 tmp = Math.abs(true);
 ok(tmp === 1, "Math.abs(true) = " + tmp);
 
+tmp = Math.abs();
+ok(isNaN(tmp), "Math.abs() is not NaN");
+
+tmp = Math.abs(NaN);
+ok(isNaN(tmp), "Math.abs() is not NaN");
+
+tmp = Math.abs(-Infinity);
+ok(tmp === Infinity, "Math.abs(-Infinite) = " + tmp);
+
 tmp = Math.abs(-3, 2);
 ok(tmp === 3, "Math.abs(-3, 2) = " + tmp);