RFR: 8356075: Support Shenandoah GC in JVMCI [v3]

[Roman Kennke]

> In order to support Shenandoah GC in Graal, some changes are required in JVMCI, namely, export Shenandoah relevant symbols.
> 
> Testing:
>  - [x] extensive testing with https://github.com/oracle/graal/pull/10904

Roman Kennke has updated the pull request incrementally with one additional commit since the last revision:

  Align backslashes

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Changes:
  - all: https://git.openjdk.org/jdk/pull/25001/files
  - new: https://git.openjdk.org/jdk/pull/25001/files/c95313a9..44344585

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25001&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25001&range=01-02

  Stats: 6 lines in 1 file changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/25001.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25001/head:pull/25001

PR: https://git.openjdk.org/jdk/pull/25001