Add check for ARM to set WOLFSS_USE_ALIGN

Author: embhorn

wolfssl/wolfcrypt/types.h

@@ -1706,6 +1706,19 @@ WOLFSSL_API word32 CheckRunTimeSettings(void);
 #endif /* WOLFSSL_AESNI || WOLFSSL_ARMASM || USE_INTEL_SPEEDUP || \
         * WOLFSSL_AFALG_XILINX */
 
+/* ARM C-only builds: if the toolchain reports that the target does NOT
+ * support unaligned access, force the alignment-safe code paths. This
+ * catches Cortex-M (ARMv6-M, and ARMv7-M/v8-M built with
+ * -mno-unaligned-access) without penalizing unaligned-capable cores
+ * such as Cortex-A and AArch64. __ARM_FEATURE_UNALIGNED is defined by
+ * GCC, Clang and armclang per the ARM ACLE when unaligned access is
+ * available. */
+#if defined(__arm__) && !defined(__ARM_FEATURE_UNALIGNED)
+    #ifndef WOLFSSL_USE_ALIGN
+        #define WOLFSSL_USE_ALIGN
+    #endif
+#endif
+
 /* Helpers for memory alignment */
 #ifndef XALIGNED
     #if defined(__GNUC__) || defined(__llvm__) || \