jvm.h and jmm.h define the internal interface between JVM and the core libraries and management.

JEP 201 defines the modular source layout and specifies src/$MODULE/{share,$OS}/include for external exported header files such as jni.h, jvmti.h.

src/$MODULE/{share,$OS}/include is not really intended for the header files for JDK internal interfaces. The current makefile Copy-java.base.gmk filters the JDK internal headers from copying to java.base.jmod.

The consolidated repo makes it possible to remove the duplicated jvm.h, jvm_md.h and jmm.h which is a great cleanup.

We should revisit the source location of JDK internal interfaces. Some possible options to consider:

1. src/hotspot/share/include and src/hotspot/os/$OS/include
2. src/java.base/{share, $OS}/include/internal and
    src/java.management/{share, $OS}/include/internal