Fix build error with legacy DDR tools

[keithc-ca]

The legacy DDR tooling apparently doesn't support use of (nested) enum literals.

[keithc-ca]

@tajila This is close to what you had originally proposed - sorry for the churn.

[fjeremic]

Curious, what is the legacy DDR tooling used for? When did we switch to the non-legacy version? Would love to understand the history of the tool.

[pshipton]

jenkins compile zlinux jdk8

[keithc-ca]

IBM internal builds of Java 8 use the same (legacy) tools they always have. See #378 for more information about the tools used externally and in other versions.

[pshipton]

I think #11144 broke aix jdk15 compiles as well.
https://ci.eclipse.org/openj9/job/Build_JDK15_ppc64_aix_Nightly/104

22:49:07  /home/jenkins/workspace/Build_JDK15_ppc64_aix_Nightly/openj9/debugtools/DDR_VM/src/com/ibm/j9ddr/vm29/j9/ObjectFieldInfo.java:27: error: cannot find symbol
22:49:07  import static com.ibm.j9ddr.vm29.structure.ObjectFieldInfo.OBJECT_SIZE_INCREMENT_IN_BYTES;
22:49:07  ^
22:49:07    symbol:   static OBJECT_SIZE_INCREMENT_IN_BYTES
22:49:07    location: class ObjectFieldInfo

jenkins compile aix jdk15

[pshipton]

@keithc-ca pls see the build failure.

[keithc-ca]

Fixed typo in reference to SIZEOF field.

[keithc-ca]

Jenkins compile zlinux jdk8

[keithc-ca]

Jenkins compile aix jdk15

[pshipton]

The builds have passed, although jenkins was restarted and AIX isn't finished uploading results.