Revert "cpp_dummy_build: Remove dependency on compat-1.3.h"
Revert "cpp_dummy_build: Remove dependency on compat-1.3.h"

There is now a test that ensures all headers are included in the
cpp_dummy_build test, so we can't remove compat-1.3.h from the
cpp_dummy_build test until we remove compat-1.3.h.

This reverts commit 2b725ef727583c95eed05e33acdbdc71997a9a9e.

Mbed-TLS/mbedtls,NXPmicro/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls,NXPmicro/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls