RFR: JDK-8266795: Remove dead code LowMemoryDetectorDisabler

[Hamlin Li]

This is trivial change to remove dead code in low memory detector.

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Commit messages:
 - Merge branch 'openjdk:master' into remove-LowMemoryDetectorDisabler
 - JDK-8266795: remove dead code LowMemoryDetectorDisabler

Changes: https://git.openjdk.java.net/jdk/pull/3964/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3964&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8266795
  Stats: 15 lines in 1 file changed: 0 ins; 14 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3964.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3964/head:pull/3964

PR: https://git.openjdk.java.net/jdk/pull/3964