Don't try to enable use of ARM NEON intrinsics when compiling in CUDA device…

Don't try to enable use of ARM NEON intrinsics when compiling in CUDA device mode. They are not available in that configuration, even if the host supports them.

PiperOrigin-RevId: 468232254
Change-Id: I1cd26eda2962778b62135a31f477928c3bde1124

absl/base/config.h

@@ -915,9 +915,14 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
 
 
 // ABSL_INTERNAL_HAVE_ARM_NEON is used for compile-time detection of NEON (ARM
 // ABSL_INTERNAL_HAVE_ARM_NEON is used for compile-time detection of NEON (ARM
 // SIMD).
 // SIMD).
+//
+// If __CUDA_ARCH__ is defined, then we are compiling CUDA code in device mode.
+// In device mode, NEON intrinsics are not available, regardless of host
+// platform.
+// https://llvm.org/docs/CompileCudaWithLLVM.html#detecting-clang-vs-nvcc-from-code
 #ifdef ABSL_INTERNAL_HAVE_ARM_NEON
 #ifdef ABSL_INTERNAL_HAVE_ARM_NEON
 #error ABSL_INTERNAL_HAVE_ARM_NEON cannot be directly set
 #error ABSL_INTERNAL_HAVE_ARM_NEON cannot be directly set
-#elif defined(__ARM_NEON)
+#elif defined(__ARM_NEON) && !defined(__CUDA_ARCH__)
 #define ABSL_INTERNAL_HAVE_ARM_NEON 1
 #define ABSL_INTERNAL_HAVE_ARM_NEON 1
 #endif
 #endif