RFR: 8287205: generate_cont_thaw generates dead code after jump to exception handler

[Richard Reingruber]

This fix avoids generating unreachable instructions after the jump to the exception handler in `generate_cont_thaw()`

Testing:

jtreg:test/hotspot/jtreg:hotspot_loom
jtreg:test/jdk:jdk_loom

On linux x86_64 and aarch64.

On aarch64 the test `jdk/java/lang/management/ThreadMXBean/VirtualThreadDeadlocks.java` had a timeout. The aaarch64 machine I used is very slow. This might have caused the timeout.

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Commit messages:
 - Merge branch 'master' into 8287205_remove_dead_code_from_generate_cont_thaw
 - Remove dead code from generate_cont_thaw

Changes: https://git.openjdk.java.net/jdk/pull/8863/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8863&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8287205
  Stats: 16 lines in 2 files changed: 8 ins; 8 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8863.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8863/head:pull/8863

PR: https://git.openjdk.java.net/jdk/pull/8863