Fixed build for older toolchains that don't have arm_sve.h

include/SDL3/SDL_intrin.h

@@ -290,7 +290,8 @@ _m_prefetch(void *__P)
 #    endif
 #  elif defined(SDL_PLATFORM_MACOS)
 /* Apple has no AArch64 device supporting SVE2 */
-#  elif defined(__ARM_ARCH) && (__ARM_ARCH >= 8) && (defined(__aarch64__) || defined(_M_ARM64))
+#  elif defined(__ARM_ARCH) && (__ARM_ARCH >= 8) && (defined(__aarch64__) || defined(_M_ARM64)) && \
+        defined(__has_include) && __has_include(<arm_sve.h>)
 #    define SDL_SVE2_INTRINSICS 1
 #    include <arm_sve.h>
 #  endif