[jdk17u] RFR: 8274550: c2i entry barriers read int as long on PPC

[Martin Doerr]

Clean backport of JDK-8274550.

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Commit messages:
 - Backport 5e4b514e6e7e1b9f51fac1983b6c12a988f7f5a8

Changes: https://git.openjdk.java.net/jdk17u/pull/192/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=192&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274550
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/192.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/192/head:pull/192

PR: https://git.openjdk.java.net/jdk17u/pull/192