Merge pull request #5469 from Unity-Technologies/windows-arm64-workaround

Don't inline mbedtls_mpi_safe_cond_assign on MSVC/ARM64 to avoid a compiler bug

library/constant_time.c

@@ -533,6 +533,13 @@ cleanup:
  * about whether the assignment was made or not.
  * (Leaking information about the respective sizes of X and Y is ok however.)
  */
+#if defined(_MSC_VER) && defined(_M_ARM64) && (_MSC_FULL_VER < 193131103)
+/*
+ * MSVC miscompiles this function if it's inlined prior to Visual Studio 2022 version 17.1. See:
+ * https://developercommunity.visualstudio.com/t/c-compiler-miscompiles-part-of-mbedtls-library-on/1646989
+ */
+__declspec(noinline)
+#endif
 int mbedtls_mpi_safe_cond_assign( mbedtls_mpi *X,
                                   const mbedtls_mpi *Y,
                                   unsigned char assign )