AK: Add constructor to create Span from Array

It's a convenience constructor. But it also seems more consistent
to allow a Span being made from both raw and managed arrays.

AK/Span.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <AK/Array.h>
 #include <AK/Assertions.h>
 #include <AK/Iterator.h>
 #include <AK/TypedTransfer.h>
@@ -33,6 +34,21 @@ public:
     {
     }
 
+    template<size_t size>
+    ALWAYS_INLINE constexpr Span(Array<T, size>& array)
+        : m_values(array.data())
+        , m_size(size)
+    {
+    }
+
+    template<size_t size>
+    requires(IsConst<T>)
+        ALWAYS_INLINE constexpr Span(Array<T, size> const& array)
+        : m_values(array.data())
+        , m_size(size)
+    {
+    }
+
 protected:
     T* m_values { nullptr };
     size_t m_size { 0 };