RFR: 8263352: assert(use == polladr) failed: the use should be a safepoint polling [v2]

[Wang Huang]

> The main reason of this failure has been shown in JDK-8263352.
> * JDK-8260637 makes a CastPP unpinned, so it can be pull out of inner loop
> * JDK-8247307 assert use == polladr and makes it crash here.
> * I think we can only `intrinsify_fill` the array when it is *really* safe here, so I fix this bug by `return` other cases.
> In this patch, I will give a small test case called `Test8263352.java` to reproduct this failure.
> Thanks to @vnkozlov , who found this failure for the first time (to me).
> Thanks to  @nsjian，who found the case which can reproduct this failure everytime.
> Thanks to @pfustc, who changed notes with us.

Wang Huang has updated the pull request incrementally with one additional commit since the last revision:

  rename testcase file

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3061/files
  - new: https://git.openjdk.java.net/jdk/pull/3061/files/7acd73d5..d0e7a27d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3061&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3061&range=00-01

  Stats: 152 lines in 2 files changed: 78 ins; 74 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3061.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3061/head:pull/3061

PR: https://git.openjdk.java.net/jdk/pull/3061