RFR: 8265784: [C2] Hoisting of DecodeN leaves MachTemp inputs behind [v2]

[Martin Doerr]

> PPC64 and s390 have DecodeN implementations which use a MachTemp input. When LCM hoists the DecodeN, the MachTemp nodes reside in the old block, but should get hoisted together with the DecodeN node.
> Same is true for load Base input which exists on s390 for example. Unfortunately, that's just a platform specific MachNode which is not nicely recognizable in LCM.

Martin Doerr has updated the pull request incrementally with one additional commit since the last revision:

  Add temp node placement assertion.

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3637/files
  - new: https://git.openjdk.java.net/jdk/pull/3637/files/86a4a6a8..0c893cd4

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3637&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3637&range=00-01

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3637.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3637/head:pull/3637

PR: https://git.openjdk.java.net/jdk/pull/3637