RFR: 8264063: Outer Safepoint poll load should not reference the head of inner strip mined loop.

[Vladimir Kozlov]

When loop is "strip mined" polling address load ([parse1.cpp#L2280](https://github.com/openjdk/jdk/blob/master/src/hotspot/share/opto/parse1.cpp#L2280)) should be cloned together with safepoint node and pinned outside inner loop. Otherwise we have issues like [8263352](https://bugs.openjdk.java.net/browse/JDK-8263352)

I also remove leftover (unused needs_polling_address_input() method) from  [8220051](https://bugs.openjdk.java.net/browse/JDK-8220051) changes.

Tested hs-tier1-4

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Commit messages:
 - 8264063: Outer Safepoint poll load should not reference the head of inner strip mined loop.

Changes: https://git.openjdk.java.net/jdk/pull/3365/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3365&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8264063
  Stats: 47 lines in 6 files changed: 10 ins; 36 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3365.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3365/head:pull/3365

PR: https://git.openjdk.java.net/jdk/pull/3365