[JVMCI] [11u] Partial backport of JDK-8220623: InstalledCode

 JDK-8220623 available in JDK 13 and better includes an update to InstalledCode class making getAddress() and getEntryPoint() methods no longer final.

In GraalVM those methods are overriden in latest code thus breaking the build using plain OpenJDK 11u as base JDK:

substratevm/src/com.oracle.svm.graal/src/com/oracle/svm/graal/meta/SubstrateInstalledCodeImpl.java:67: error: getAddress() in SubstrateInstalledCodeImpl cannot override getAddress() in InstalledCode
    public long getAddress() {
                ^
  overridden method is final
substratevm/src/com.oracle.svm.graal/src/com/oracle/svm/graal/meta/SubstrateInstalledCodeImpl.java:73: error: getEntryPoint() in SubstrateInstalledCodeImpl cannot override getEntryPoint() in InstalledCode
    public long getEntryPoint() {
                ^
  overridden method is final
2 errors

As backporting all of JDK-8220623 is too risky for a stable JDK release we should consider only a partial backport including changes to InstalledCode.java only which is a lot less risky.