Merge pull request #10538 from gilles-peskine-arm/include-common-first-fix-aesce-3.6

Backport 3.6: Fix AESCE regression with Clang due to inclusion order changes

library/aesce.c

@@ -5,10 +5,6 @@
  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
  */
 
-#include "common.h"
-
-#if defined(MBEDTLS_AESCE_C)
-
 #if defined(__clang__) &&  (__clang_major__ >= 4)
 
 /* Ideally, we would simply use MBEDTLS_ARCH_IS_ARMV8_A in the following #if,
@@ -20,15 +16,16 @@
 #endif
 
 #if defined(MBEDTLS_AESCE_ARCH_IS_ARMV8_A) && !defined(__ARM_FEATURE_CRYPTO)
-/* TODO: Re-consider above after https://reviews.llvm.org/D131064 merged.
- *
- * The intrinsic declaration are guarded by predefined ACLE macros in clang:
+/* The intrinsic declaration are guarded by predefined ACLE macros in clang:
  * these are normally only enabled by the -march option on the command line.
  * By defining the macros ourselves we gain access to those declarations without
  * requiring -march on the command line.
  *
  * `arm_neon.h` is included by common.h, so we put these defines
- * at the top of this file, before any includes.
+ * at the top of this file, before any includes. This is necessary with
+ * Clang <=15.x. With Clang 16.0 and above, these macro definitions are
+ * no longer required, but they're harmless. See
+ * https://reviews.llvm.org/D131064
  */
 #define __ARM_FEATURE_CRYPTO 1
 /* See: https://arm-software.github.io/acle/main/acle.html#cryptographic-extensions
@@ -42,6 +39,10 @@
 
 #endif /* defined(__clang__) &&  (__clang_major__ >= 4) */
 
+#include "common.h"
+
+#if defined(MBEDTLS_AESCE_C)
+
 #include <string.h>
 
 #include "aesce.h"