RFR: 8301095: [s390x] TestDwarf.java fails [v4]

[Amit Kumar]

> TestDwarf.java fails on s390 due to incorrect returned frame. for dereference_null crash, the (return) pc was selected from gpr14 (in accordance with z-ABI) but correct (return) pc was present at "return_pc" offset. This PR introduces an additional check for the frame type detection. 
> Special Thanks to @RealLucy

Amit Kumar has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains five commits:

 - Merge branch 'master' into test_dwarf
 - addressing Lutz comments
 - no need to fetch sender_sp again
 - updates header year
 - adds additional check for frame detection

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Changes: https://git.openjdk.org/jdk/pull/12306/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12306&range=03
  Stats: 9 lines in 1 file changed: 7 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/12306.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12306/head:pull/12306

PR: https://git.openjdk.org/jdk/pull/12306