As a prerequisite for JDK-8344009, TracePhase constructor needs to know in the PhaseTraceId. And while we are at it, it can be simplified: trace strings can be kept in via x-macro with the IDs, and it is sufficient to pass in the IDs, no need to pass the pointer to the counters since we use the same counters anyway.

Since this is a somewhat invasive but purely mechanical change, I separate this work from JDK-8344009.