RFR: 8279535: C2: Dead code in PhaseIdealLoop::create_loop_nest after JDK-8276116

[Roland Westrelin]

Removal of a couple lines of dead code.

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Commit messages:
 - fix

Changes: https://git.openjdk.java.net/jdk/pull/7309/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7309&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8279535
  Stats: 3 lines in 1 file changed: 0 ins; 3 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7309.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7309/head:pull/7309

PR: https://git.openjdk.java.net/jdk/pull/7309