RFR: 8293293: Move archive heap loading code out of heapShared.cpp

[Ioi Lam]

I moved all code related to loading the archive heap regions into a new file, archiveHeapLoader.cpp.

A diff of the new archiveHeapLoader.cpp and the old heapShared.cpp shows that the moved code is identical, except for the change of `HeapShared::` to `ArchiveHeapLoader::`.

I also removed unnecessary entries in JVM_EXCLUDE_FILES that are already covered by the `cds/` pattern.

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Commit messages:
 - 8293293: Move archive heap loading code out of heapShared.cpp

Changes: https://git.openjdk.org/jdk/pull/10138/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10138&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293293
  Stats: 1318 lines in 19 files changed: 716 ins; 554 del; 48 mod
  Patch: https://git.openjdk.org/jdk/pull/10138.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10138/head:pull/10138

PR: https://git.openjdk.org/jdk/pull/10138