AK: Make Concepts.h and StdLibExtras.h properly alias their own sumbols.

Author: https://github.com/mhermier
Commit: https://github.com/SerenityOS/serenity/commit/b8fac0a8b30
Pull-request: https://github.com/SerenityOS/serenity/pull/5994

AK/Concepts.h

@@ -47,8 +47,8 @@ concept Arithmetic = IsArithmetic<T>::value;
 
 #if defined(__cpp_concepts) && !defined(__COVERITY__)
 
-using AK::IsArithmetic;
-using AK::IsFloatingPoint;
-using AK::IsIntegral;
+using AK::Concepts::Arithmetic;
+using AK::Concepts::FloatingPoint;
+using AK::Concepts::Integral;
 
 #endif

AK/StdLibExtras.h

@@ -618,7 +618,9 @@ using AK::IsBaseOf;
 using AK::IsClass;
 using AK::IsConst;
 using AK::IsEnum;
+using AK::IsFloatingPoint;
 using AK::IsFundamental;
+using AK::IsIntegral;
 using AK::IsNullPointer;
 using AK::IsSame;
 using AK::IsUnion;