RFR: 8261662: Rename compute_loader_lock_object

[Coleen Phillimore]

Hopefully trivial change to rename this function.  Tested with tier1 on linux, windows & macos.

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Commit messages:
 - 8261662: Rename compute_loader_lock_object

Changes: https://git.openjdk.java.net/jdk/pull/2552/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2552&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8261662
  Stats: 7 lines in 3 files changed: 0 ins; 0 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2552.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2552/head:pull/2552

PR: https://git.openjdk.java.net/jdk/pull/2552