[jdk17u] RFR: 8273606: Zero: SPARC64 build fails with si_band type mismatch

[Aleksey Shipilev]

Fixes the corner case in Zero/SPARC64 build. The change is no-op for the well-behaved libc.

Additional testing:
 - [x] Linux Zero/SPARC64 cross-compilation fails without the patch, passes with the patch

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Commit messages:
 - Backport 241ac89f120f9bcfef65962aa05b51b9f847c4ce

Changes: https://git.openjdk.java.net/jdk17u/pull/138/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=138&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8273606
  Stats: 5 lines in 1 file changed: 4 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/138.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/138/head:pull/138

PR: https://git.openjdk.java.net/jdk17u/pull/138