RFR: 8264800: cleanup Threads_lock comments in JVM/TI function headers

[Daniel D.Daugherty]

A trivial fix to cleanup Threads_lock comments in JVM/TI function headers.

Also remove errant text added by the jframeID XSL template code:


// java_thread - unchecked
// depth - pre-checked as non-negative


The first line about `jthread` is output in error.
Only the second line about `depth` should be included.

This fix is tested with a Mach5 Tier1 job set.

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Commit messages:
 - 8264800: cleanup Threads_lock comments in JVM/TI function headers

Changes: https://git.openjdk.java.net/jdk/pull/4254/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4254&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8264800
  Stats: 91 lines in 3 files changed: 0 ins; 52 del; 39 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4254.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4254/head:pull/4254

PR: https://git.openjdk.java.net/jdk/pull/4254