compat: always use _aligned_malloc/_aligned_free on Windows

We don't need the mingw custom code. It's available in msvcrt.dll and UCRT. It's better
to use the same code between mingw and MSVC builds.

compat/aligned_alloc.c

@@ -56,9 +56,7 @@ void *aligned_alloc(size_t align, size_t size)
 
 #elif defined(HAVE_MEMALIGN)
     return memalign(align, size);
-#elif defined (_WIN32) && defined(__MINGW32__)
-    return __mingw_aligned_malloc(size, align);
-#elif defined (_WIN32) && defined(_MSC_VER)
+#elif defined (_WIN32)
     return _aligned_malloc(size, align);
 #else
     /* align must be valid/supported */

include/vlc_fixups.h

@@ -396,9 +396,7 @@ void *aligned_alloc(size_t, size_t);
 } /* extern "C" */
 #endif
 
-#if defined (_WIN32) && defined(__MINGW32__)
-#define aligned_free(ptr)  __mingw_aligned_free(ptr)
-#elif defined (_WIN32) && defined(_MSC_VER)
+#if defined (_WIN32)
 #define aligned_free(ptr)  _aligned_free(ptr)
 #else
 #define aligned_free(ptr)  free(ptr)