RFR: 8284198: Undo JDK-8261137: Optimization of Box nodes in uncommon_trap [v5]

[Wu Yan]

> [JDK-8261137](https://bugs.openjdk.java.net/browse/JDK-8261137) introduced a regression and has been disabled by [JDK-8276112](https://bugs.openjdk.java.net/browse/JDK-8276112). Better to revert the changes of the optimization instead of letting the dead-code decay.
> 
> This reverts [JDK-8261137](https://bugs.openjdk.java.net/browse/JDK-8261137) and [JDK-8264940](https://bugs.openjdk.java.net/browse/JDK-8264940), my tier1 testing on linux-x86 passed.

Wu Yan has updated the pull request incrementally with one additional commit since the last revision:

  keep TestIdentityWithEliminateBoxInDebugInfo

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8083/files
  - new: https://git.openjdk.java.net/jdk/pull/8083/files/b786f7e0..1fccd48b

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8083&range=04
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8083&range=03-04

  Stats: 116 lines in 3 files changed: 114 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8083.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8083/head:pull/8083

PR: https://git.openjdk.java.net/jdk/pull/8083