RFR: 8328236: module_entry in CDS map file has stale value

[Ioi Lam]

When a `java.lang.Module` object is copied into the CDS archive, we clear its `module_entry` field to 0. However, the information printed in the cds.map file still shows a non-zero value:

$ java -Xshare:dump -Xlog:cds+map=debug,cds+map+oops=trace:file=cds.map:none:filesize=0
$ cat cds.map | grep module_entry
...
 - injected 'module_entry' 'J' @16  140166528907408 (0x00007f7b102a3890)


The reason is the above is printed using the "original" Module object whose `module_entry` is not cleared. We only clear  this object's "buffered copy", which is the one that gets written into the CDS archive.

The fix is to change the printing code to use the "buffered copy" instead. Now it looks like this:


 - injected 'module_entry' 'J' @16  0 (0x0000000000000000)

-------------

Commit messages:
 - 8328236: module_entry in CDS map file has stale value

Changes: https://git.openjdk.org/jdk/pull/18320/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18320&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8328236
  Stats: 19 lines in 2 files changed: 10 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/18320.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18320/head:pull/18320

PR: https://git.openjdk.org/jdk/pull/18320