RFR: 8378076: Improve inlining around oop_oop_iterate

[Ivan Walulya]

Please review this change to improve inlining around `oop_oop_iterate`. The change improves `Concurrent Mark From Roots` in BigRamTester (BRT) by ~15 - 20%.

Before:

[59.292s][info   ][gc,marking] GC(10) Concurrent Mark From Roots 5366.043ms
[165.244s][info   ][gc,marking] GC(19) Concurrent Mark From Roots 5537.965ms
[270.502s][info   ][gc,marking] GC(29) Concurrent Mark From Roots 5587.758ms
[365.912s][info   ][gc,marking] GC(38) Concurrent Mark From Roots 5471.903ms
[492.253s][info   ][gc,marking] GC(48) Concurrent Mark From Roots 5146.705ms

After:

[52.924s][info   ][gc,marking] GC(8) Concurrent Mark From Roots 4419.289ms
[156.467s][info   ][gc,marking] GC(17) Concurrent Mark From Roots 4540.361ms
[263.955s][info   ][gc,marking] GC(27) Concurrent Mark From Roots 4630.036ms
[361.794s][info   ][gc,marking] GC(36) Concurrent Mark From Roots 4780.361ms
[483.695s][info   ][gc,marking] GC(46) Concurrent Mark From Roots 4480.253ms


For the BigArrayScanTest attached to [JDK-8057003](https://bugs.openjdk.org/browse/JDK-8057003):

Before:

[0.033s][info ][gc,marking] GC(1) Concurrent Mark From Roots 2.759ms
[6.983s][info ][gc,marking] GC(9) Concurrent Mark From Roots 3474.147ms
[15.181s][info ][gc,marking] GC(29) Concurrent Mark From Roots 3405.123ms
[22.045s][info ][gc,marking] GC(35) Concurrent Mark From Roots 3261.046ms
[28.802s][info ][gc,marking] GC(41) Concurrent Mark From Roots 2714.513ms


After:

[0.033s][info ][gc,marking] GC(1) Concurrent Mark From Roots 2.699ms
[5.738s][info ][gc,marking] GC(9) Concurrent Mark From Roots 2345.396ms
[12.808s][info ][gc,marking] GC(27) Concurrent Mark From Roots 3288.624ms
[20.477s][info ][gc,marking] GC(34) Concurrent Mark From Roots 2604.406ms
[27.397s][info ][gc,marking] GC(40) Concurrent Mark From Roots 2499.408ms


Mach5 Testing: Tier 1-3

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

Commit messages:
 - init

Changes: https://git.openjdk.org/jdk/pull/29755/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29755&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8378076
  Stats: 4 lines in 2 files changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/29755.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29755/head:pull/29755

PR: https://git.openjdk.org/jdk/pull/29755