RFR: 8355490: Make VM_RedefineClasses::merge_constant_pools only take reference arguments [v2]

[Johan Sjölen]

> Hi,
> 
> I've changed two pointer arguments to be references instead, as we bail if they are null and `assert(false)` on top of that. There are no other calls to this function than the one I fixed.
> 
> Testing: GHA Tier1

Johan Sjölen has updated the pull request incrementally with one additional commit since the last revision:

  Copyright

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Changes:
  - all: https://git.openjdk.org/jdk/pull/24848/files
  - new: https://git.openjdk.org/jdk/pull/24848/files/55d8994d..abf2fc71

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24848&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24848&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/24848.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24848/head:pull/24848

PR: https://git.openjdk.org/jdk/pull/24848