[jdk11u-dev] RFR: 8282306: os::is_first_C_frame(frame*) crashes on invalid link access [v2]

[Johannes Bechberger]

> Hardening os::is_first_C_frame(frame*) against accesses on invalid links.
> 
> Applies relatively clean (only a comment changed which hindered it from applying directly).
> 
> Tested via nightly SAP builds and on my own linux machine.

Johannes Bechberger has updated the pull request incrementally with one additional commit since the last revision:

  Readd removed lines

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

Changes:
  - all: https://git.openjdk.org/jdk11u-dev/pull/1373/files
  - new: https://git.openjdk.org/jdk11u-dev/pull/1373/files/9383888d..7e6b84e2

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1373&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1373&range=00-01

  Stats: 7 lines in 1 file changed: 7 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1373.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev pull/1373/head:pull/1373

PR: https://git.openjdk.org/jdk11u-dev/pull/1373