Alter constant-flow memsan testing

Disable asm in memsan constant-flow testing and add a check in
check_config.h

Signed-off-by: Elena Uziunaite <elena.uziunaite@arm.com>
diff --git a/tests/scripts/components-sanitizers.sh b/tests/scripts/components-sanitizers.sh
index 31aae31..2eb2b0f 100644
--- a/tests/scripts/components-sanitizers.sh
+++ b/tests/scripts/components-sanitizers.sh
@@ -49,6 +49,7 @@
     scripts/config.py set MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN
     scripts/config.py unset MBEDTLS_USE_PSA_CRYPTO
     scripts/config.py unset MBEDTLS_AESNI_C # memsan doesn't grok asm
+    scripts/config.py unset MBEDTLS_HAVE_ASM
     CC=clang cmake -D CMAKE_BUILD_TYPE:String=MemSan .
     make
 
@@ -67,6 +68,7 @@
     scripts/config.py full
     scripts/config.py set MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN
     scripts/config.py unset MBEDTLS_AESNI_C # memsan doesn't grok asm
+    scripts/config.py unset MBEDTLS_HAVE_ASM
     CC=clang cmake -D CMAKE_BUILD_TYPE:String=MemSan .
     make