There is support in JVMCI for writing to HotSpot's CompileLog stream[1].
The next step is to use this support to have Graal emit compilation events to the log. It would allow tools such as JITWatch[2] to work with Graal.

[1] https://github.com/graalvm/graal-jvmci-8/blob/145ecfd1b505692a97bb7aa2a9b24d2d21b3bc98/jvmci/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotJVMCIRuntime.java#L798
[2] https://github.com/AdoptOpenJDK/jitwatch/wiki