RFR: JDK-8272698: LoadNode::pin is unused

[Tobias Holenstein]

Removed dead code and tested on Tier 1.

Thanks, 
Tobias

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Commit messages:
 - JDK-8272698: LoadNode::pin is unused

Changes: https://git.openjdk.java.net/jdk/pull/5408/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5408&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8272698
  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5408.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5408/head:pull/5408

PR: https://git.openjdk.java.net/jdk/pull/5408