RFR: 8340623: remove outdated PROCESSOR_ARCHITECTURE_IA64 from Windows coding

[Matthias Baesken]

We still check for PROCESSOR_ARCHITECTURE_IA64 but this is not supported any more for a very long time in OpenJDK.

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Commit messages:
 - JDK-8340623

Changes: https://git.openjdk.org/jdk/pull/21130/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21130&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8340623
  Stats: 3 lines in 1 file changed: 0 ins; 3 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/21130.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21130/head:pull/21130

PR: https://git.openjdk.org/jdk/pull/21130