RFR: Reverted unrelated, wrong or unused changes

[Robbin Ehn]

Reverted to master unrelated, wrong or unused changes.

Running loom-t1

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Commit messages:
 - Rev vmError.cpp
 - Reverted safepoint.xpp
 - Reverted prefetch
 - Reverted objectMonitor.inline.hpp
 - Reverted interfaceSupport.inline.hpp
 - Removed added extra space

Changes: https://git.openjdk.java.net/loom/pull/126/files
 Webrev: https://webrevs.openjdk.java.net/?repo=loom&pr=126&range=00
  Stats: 45 lines in 13 files changed: 2 ins; 41 del; 2 mod
  Patch: https://git.openjdk.java.net/loom/pull/126.diff
  Fetch: git fetch https://git.openjdk.java.net/loom pull/126/head:pull/126

PR: https://git.openjdk.java.net/loom/pull/126