RFR: 8264063: Outer Safepoint poll load should not reference the head of inner strip mined loop. [v2]

[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

Vladimir Kozlov has updated the pull request incrementally with one additional commit since the last revision:

  Removed unneeded anymore code in match_fill_loop()

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3365/files
  - new: https://git.openjdk.java.net/jdk/pull/3365/files/1f645337..58a4ce1d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3365&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3365&range=00-01

  Stats: 10 lines in 1 file changed: 0 ins; 10 del; 0 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