AK: Make IsUnsigned<T> behave as you would expect

AK/StdLibExtras.h

@@ -533,7 +533,7 @@ template<typename... _Ignored>
 constexpr auto DependentFalse = false;
 
 template<typename T>
-using IsUnsigned = IsSame<T, MakeUnsigned<T>>;
+using IsUnsigned = IsSame<T, typename MakeUnsigned<T>::Type>;
 
 template<typename T>
 using IsArithmetic = IntegralConstant<bool, IsIntegral<T>::value || IsFloatingPoint<T>::value>;
@@ -620,6 +620,7 @@ using AK::IsFundamental;
 using AK::IsNullPointer;
 using AK::IsSame;
 using AK::IsUnion;
+using AK::IsUnsigned;
 using AK::IsVoid;
 using AK::MakeIndexSequence;
 using AK::MakeIntegerSequence;

AK/Tests/TestTypeTraits.cpp

@@ -80,6 +80,15 @@ TEST_CASE(FundamentalTypeClassification)
     EXPECT_TRAIT_TRUE(IsFundamental, unsigned short, unsigned int, unsigned long, unsigned long long);
 
     EXPECT_TRAIT_FALSE(IsFundamental, Empty, int*, int&);
+
+    EXPECT_TRAIT_TRUE(IsUnsigned, unsigned);
+    EXPECT_TRAIT_TRUE(IsUnsigned, unsigned short);
+    EXPECT_TRAIT_TRUE(IsUnsigned, unsigned char);
+    EXPECT_TRAIT_TRUE(IsUnsigned, unsigned long);
+    EXPECT_TRAIT_FALSE(IsUnsigned, int);
+    EXPECT_TRAIT_FALSE(IsUnsigned, short);
+    EXPECT_TRAIT_FALSE(IsUnsigned, char);
+    EXPECT_TRAIT_FALSE(IsUnsigned, long);
 }
 
 TEST_CASE(AddConst)