AK: Add clamp_to_int(value) in Math.h

clamp_to_int clamps value to valid range of int values so resulting
value does not overflow.

It is going to be used to clamp float or double values to int that
represents fixed-point value of CSSPixels.

AK/Math.h

@@ -906,6 +906,17 @@ constexpr T round(T x)
     return ceil(x - .5);
 }
 
+template<typename T>
+constexpr int clamp_to_int(T value)
+{
+    if (value >= NumericLimits<int>::max()) {
+        return NumericLimits<int>::max();
+    } else if (value <= NumericLimits<int>::min()) {
+        return NumericLimits<int>::min();
+    }
+    return value;
+}
+
 #undef CONSTEXPR_STATE
 #undef AARCH64_INSTRUCTION
 }