RFR: 8290246: test fails "assert(init != __null) failed: initialization not found" [v2]

[Vladimir Kozlov]

> CTW test (which compiles methods without running them - no profiling) failed when run with stress flag and particular RNG seed `-XX:+StressIGVN -XX:StressSeed=1743550013`. The failure is intermittent because of RNG.
> 
> The compiled method [BasicPopupMenuUI$BasicMenuKeyListener::menuKeyPressed()](https://github.com/openjdk/jdk/blob/master/src/java.desktop/share/classes/javax/swing/plaf/basic/BasicPopupMenuUI.java#L331) has allocation in loop at line [L360](https://github.com/openjdk/jdk/blob/master/src/java.desktop/share/classes/javax/swing/plaf/basic/BasicPopupMenuUI.java#L360) which is followed by call `item.isArmed()` at line L366. This call is not "linked" and uncommon trap is generated for it. As result the allocation result become un-used.
> Due to shuffling done with `StressIGVN` flag LoadRangeNode is processed after InitializeNode is removed from graph but AllocateArrayNode is not. We hit assert because of that.
> 
> The fix replaces the assert with check.
> 
> Tested with replay file from bug report. I was not able to reproduce failure with standalone test because it is hard to force LoadRangeNode processing at right time. I attached to bug report a test which work on.
> 
> Testing tier1-3,xcomp

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

  Return original length when InitializeNode is absent

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9497/files
  - new: https://git.openjdk.org/jdk/pull/9497/files/fdf46971..73b101e2

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9497&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9497&range=00-01

  Stats: 5 lines in 1 file changed: 1 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/9497.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9497/head:pull/9497

PR: https://git.openjdk.org/jdk/pull/9497