RFR: 8308903: Print detailed info for Java objects in -Xlog:cds+map

[Ioi Lam]

This PR adds detailed printing of oop information with `-Xlog:cds+map+oop=trace`, or simply `-Xlog:cds+map*=trace`. The information is useful for debugging contents of the CDS archived heap objects.

The output looks like `oopDesc::print_on(tty)`, but we need to print the pointers using the locations of the objects at runtime. The examples below show how a `String` references its `value` array.

Example with `-XX:-UseCompressedOops`:


0x00000000100001f0: @@ Object java.lang.String
0x00000000100001f0: 0000006ff6ab8d01 88d47c5b00010290 0000000000010000 0000000010000210
 - klass: 'java/lang/String' 0x0000000800010290
 - ---- fields (total size 4 words):
 - private 'hash' 'I' @12 -1999340453 (0x88d47c5b)
 - private final 'coder' 'B' @16 0 (0x00)
 - private 'hashIsZero' 'Z' @17 false (0x00)
 - injected 'flags' 'B' @18 1 (0x01)
 - private final 'value' '[B' @24 0x0000000010000210 [B length: 6
0x0000000010000210: @@ Object [B length: 6
0x0000000010000210: 000000693b708001 00000006000024c8 0000574f5252414e
 - klass: {type array byte} 0x00000008000024c8
 - 0: 4e N
 - 1: 41 A
 - 2: 52 R
 - 3: 52 R
 - 4: 4f O
 - 5: 57 W


Example with `-XX:+UseCompressedOops`. Note that the narrorOop is also printed:


0x00000007ffc001b8: @@ Object (0xfff80037) java.lang.String
0x00000007ffc001b8: f6ab8d01 0000006f 00010290 88d47c5b 00010000 fff8003a
 - klass: 'java/lang/String' 0x0000000800010290
 - ---- fields (total size 3 words):
 - private 'hash' 'I' @12 -1999340453 (0x88d47c5b)
 - private final 'coder' 'B' @16 0 (0x00)
 - private 'hashIsZero' 'Z' @17 false (0x00)
 - injected 'flags' 'B' @18 1 (0x01)
 - private final 'value' '[B' @20 0x00000007ffc001d0 (0xfff8003a) [B length: 6
0x00000007ffc001d0: @@ Object (0xfff8003a) [B length: 6
0x00000007ffc001d0: 3b708001 00000069 000024c8 00000006 5252414e 0000574f
 - klass: {type array byte} 0x00000008000024c8
 - 0: 4e N
 - 1: 41 A
 - 2: 52 R
 - 3: 52 R
 - 4: 4f O
 - 5: 57 W

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

Commit messages:
 - 8308903: Print detailed info for Java objects in -Xlog:cds+map

Changes: https://git.openjdk.org/jdk/pull/14841/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14841&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8308903
  Stats: 205 lines in 7 files changed: 164 ins; 12 del; 29 mod
  Patch: https://git.openjdk.org/jdk/pull/14841.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14841/head:pull/14841

PR: https://git.openjdk.org/jdk/pull/14841