RFR: 8353066: Properly detect Windows/aarch64 as build platform

[Magnus Ihse Bursie]

Configure does not properly detect Windows/aarch64 on Cygwin. One complicating factor here is that no native aarch64 version of Cygwin exists, so it is running x64 binaries in emulated mode.

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Commit messages:
 - 8353066: Properly detect Windows/aarch64 as build platform

Changes: https://git.openjdk.org/jdk/pull/24397/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24397&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8353066
  Stats: 10 lines in 2 files changed: 4 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/24397.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24397/head:pull/24397

PR: https://git.openjdk.org/jdk/pull/24397