RFR: 8340212: -Xshare:off -XX:CompressedClassSpaceBaseAddress=0x40001000000 crashes on macos-aarch64 [v12]

[Coleen Phillimore]

> Added checks to verify that the given compressed class base or shared base address and shift given will be decodable for aarch64.  This code is moved in PR https://github.com/openjdk/jdk/pull/20677 so this would be moved to the new place once that's integrated.
> 
> Tested with tier1-7.

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  Comment why shared_base_valid() can't actually check for us whether the shared base is valid.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/21695/files
  - new: https://git.openjdk.org/jdk/pull/21695/files/9c810609..36eae88c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21695&range=11
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21695&range=10-11

  Stats: 5 lines in 1 file changed: 2 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/21695.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21695/head:pull/21695

PR: https://git.openjdk.org/jdk/pull/21695