RFR: 8289743: AArch64: Clean up patching logic

[Andrew Haley]

The current logic for patching is a mess of if-then-elses. By rearranging the logic and using a switch we can make it both easier to understand and faster.

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Commit messages:
 - 8289743: AArch64: Clean up patching logic
 - 8289698: AArch64: Need to relativize extended_sp in frame
 - 8289743: AArch64: Clean up patching logic
 - 8289743: AArch64: Clean up patching logic
 - 8289743: AArch64: Clean up patching logic
 - 8289743: AArch64: Clean up patching logic
 - 8289743: AArch64: Clean up patching logic
 - 8289743: AArch64: Clean up patching logic
 - 8289743: AArch64: Clean up patching logic
 - 8289743: AArch64: Clean up patching logic
 - ... and 6 more: https://git.openjdk.org/jdk/compare/77c3bbf1...ee6e4189

Changes: https://git.openjdk.org/jdk/pull/9398/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9398&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8289743
  Stats: 283 lines in 5 files changed: 113 ins; 44 del; 126 mod
  Patch: https://git.openjdk.org/jdk/pull/9398.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9398/head:pull/9398

PR: https://git.openjdk.org/jdk/pull/9398