RFR: 8248404: AArch64: Remove uses of long and unsigned long

[Coleen Phillimore]

Tested with mach5 on linux-aarch64 and macosx-aarch64 on tier1-3 and below GHA for windows-aarch64 (once I open this PR).

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Commit messages:
 - remove commented out code
 - 8248404: AArch64: Remove uses of long and unsigned long

Changes: https://git.openjdk.java.net/jdk/pull/7023/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7023&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8248404
  Stats: 42 lines in 5 files changed: 9 ins; 20 del; 13 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7023.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7023/head:pull/7023

PR: https://git.openjdk.java.net/jdk/pull/7023