MSVC: drop previous workaround after MSVC broke compat

Previously the default ctor here was reported as "multiple versions of a
defaulted special member functions". Looks like the bug was fixed in
MSVC and the workaround now makes the code ill-formed.

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

Vc/common/simdarray.h

@@ -143,9 +143,7 @@ class SimdArray<T, N, VectorType_, N>
     static constexpr std::size_t MemoryAlignment = storage_type::MemoryAlignment;
 
     // zero init
-#ifndef Vc_MSVC  // bogus error C2580
     Vc_INTRINSIC SimdArray() = default;
-#endif
 
     // default copy ctor/operator
     Vc_INTRINSIC SimdArray(const SimdArray &) = default;
@@ -724,9 +722,7 @@ template <typename T, size_t N, typename V, size_t Wt> class SimdArray
     ///@{
 
     ///\copydoc Vector::Vector()
-#ifndef Vc_MSVC  // bogus error C2580
     SimdArray() = default;
-#endif
     ///@}
 
     /// \name Conversion/Broadcast Constructors