Fixed definition of builtin function '_m_prefetch'

Fixes https://github.com/libsdl-org/SDL/issues/15116

include/SDL3/SDL_endian.h

@@ -46,7 +46,7 @@
 #if defined(_MSC_VER) && (_MSC_VER >= 1400)
 /* As of Clang 11, '_m_prefetchw' is conflicting with the winnt.h's version,
    so we define the needed '_m_prefetch' here as a pseudo-header, until the issue is fixed. */
-#if defined(__clang__) &&  !SDL_HAS_BUILTIN(_m_prefetch)
+#if defined(__clang__) && !SDL_HAS_BUILTIN(_m_prefetch)
 #ifndef __PRFCHWINTRIN_H
 #define __PRFCHWINTRIN_H
 static __inline__ void __attribute__((__always_inline__, __nodebug__))

include/SDL3/SDL_intrin.h

@@ -217,9 +217,9 @@
 /* Need to do this here because intrin.h has C++ code in it */
 /* Visual Studio 2005 has a bug where intrin.h conflicts with winnt.h */
 #if defined(_MSC_VER) && (_MSC_VER >= 1500) && (defined(_M_IX86) || defined(_M_X64))
-#ifdef __clang__
 /* As of Clang 11, '_m_prefetchw' is conflicting with the winnt.h's version,
    so we define the needed '_m_prefetch' here as a pseudo-header, until the issue is fixed. */
+#if defined(__clang__) && !SDL_HAS_BUILTIN(_m_prefetch)
 #ifndef __PRFCHWINTRIN_H
 #define __PRFCHWINTRIN_H
 static __inline__ void __attribute__((__always_inline__, __nodebug__))