MSVC: Move reinterpret_components_cast below Vector<T, Abi>

MSVC requires Vector<T, Abi> to be defined before it's used in the
definition of the reinterpret_components_cast template function.
Reordering the code works around the issue.

Refs: gh-119
Signed-off-by: Matthias Kretz <kretz@kde.org>

common/vector.h

@@ -104,36 +104,6 @@ Vc_INTRINSIC Vc_CONST typename Vector<T, Abi>::MaskType isnegative(Vector<T, Abi
     return x < Vector<T, Abi>::Zero();
 }
 
-/**
- * \ingroup Utilities
- * Constructs a new Vector object of type \p V from the Vector \p x, reinterpreting the
- * bits of \p x for the new type \p V.
- *
- * This function is only applicable if:
- * - the \c sizeof of the input and output types is equal
- * - the Vector::size() of the input and output types is equal
- * - the \c VectorEntryTypes of input and output have equal \c sizeof
- *
- * \tparam V The requested type to change \p x into.
- * \param x The Vector to reinterpret as an object of type \p V.
- * \returns A new object (rvalue) of type \p V.
- *
- * \warning This cast is non-portable since the applicability (see above) may change
- * depending on the default vector types of the target platform. The function is perfectly
- * safe to use with fully specified \p Abi, though.
- */
-template <typename V, typename T, typename Abi>
-Vc_ALWAYS_INLINE Vc_CONST enable_if<
-    (V::size() == Vector<T, Abi>::size() &&
-     sizeof(typename V::VectorEntryType) ==
-         sizeof(typename Vector<T, Abi>::VectorEntryType) &&
-     sizeof(V) == sizeof(Vector<T, Abi>) && alignof(V) <= alignof(Vector<T, Abi>)),
-    V>
-reinterpret_components_cast(const Vector<T, Abi> &x)
-{
-    return reinterpret_cast<const V &>(x);
-}
-
 /**
  * \class Vector types.h <Vc/vector.h>
  * \ingroup Vectors
@@ -832,6 +802,36 @@ template<typename T, typename Abi = VectorAbi::Best<T>> class Vector
     VectorType d;
 };
 
+/**
+ * \ingroup Utilities
+ * Constructs a new Vector object of type \p V from the Vector \p x, reinterpreting the
+ * bits of \p x for the new type \p V.
+ *
+ * This function is only applicable if:
+ * - the \c sizeof of the input and output types is equal
+ * - the Vector::size() of the input and output types is equal
+ * - the \c VectorEntryTypes of input and output have equal \c sizeof
+ *
+ * \tparam V The requested type to change \p x into.
+ * \param x The Vector to reinterpret as an object of type \p V.
+ * \returns A new object (rvalue) of type \p V.
+ *
+ * \warning This cast is non-portable since the applicability (see above) may change
+ * depending on the default vector types of the target platform. The function is perfectly
+ * safe to use with fully specified \p Abi, though.
+ */
+template <typename V, typename T, typename Abi>
+Vc_ALWAYS_INLINE Vc_CONST enable_if<
+    (V::size() == Vector<T, Abi>::size() &&
+     sizeof(typename V::VectorEntryType) ==
+         sizeof(typename Vector<T, Abi>::VectorEntryType) &&
+     sizeof(V) == sizeof(Vector<T, Abi>) && alignof(V) <= alignof(Vector<T, Abi>)),
+    V>
+reinterpret_components_cast(const Vector<T, Abi> &x)
+{
+    return reinterpret_cast<const V &>(x);
+}
+
 #define Vc_OP(symbol)                                                                    \
     template <typename T, typename Abi>                                                  \
     inline Vector<T, Abi> &operator symbol##=(Vector<T, Abi> &,                          \