[master] RFR: 8300573: [Lilliput] Properly set ZF on anon-check path; avoid some conditional branches

[Roman Kennke]

In AArch64's fast_unlock(), we need to check if the monitor owner is ANONYMOUS (only with Lilliput/fast-locking), and if so, call the runtime to fix this before exiting the monitor. I tried to be smart and used tbnz there, but it turns out that tbnz does *not* set the zero flag, but we do need the ZF set correctly on exit of fast_unlock, so that C2 generated code would actually call the slow path. Therefore we need to use the longer tst/br instructions instead.

The change also removes some conditional branches.

All of the changes have already been integrated into the upstream proposed PR: https://github.com/openjdk/jdk/pull/10907/

Testing:
 - [x] tier1
 - [x] tier2

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Commit messages:
 - 8300573: [Lilliput] Properly set ZF on anon-check path; avoid some conditional branches

Changes: https://git.openjdk.org/lilliput/pull/63/files
 Webrev: https://webrevs.openjdk.org/?repo=lilliput&pr=63&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8300573
  Stats: 19 lines in 1 file changed: 12 ins; 2 del; 5 mod
  Patch: https://git.openjdk.org/lilliput/pull/63.diff
  Fetch: git fetch https://git.openjdk.org/lilliput pull/63/head:pull/63

PR: https://git.openjdk.org/lilliput/pull/63