RFR: JDK-8301621: libzip should use pread instead of lseek+read

Fri Feb 3 19:56:46 UTC 2023

Avoid using `lseek` + `read` in favor of `pread`. For Windows, we can do the same thing by using `OVERLAPPED`, as we are in synchronous mode we can use `Offset` and `OffsetHigh` to achieve the same thing.

Additionally I updated open to use `O_CLOEXEC` when available, as that really should be used.

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Commit messages:
 - Avoid extra seek syscall in libzip while reading

Changes: https://git.openjdk.org/jdk/pull/12417/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12417&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8301621
  Stats: 67 lines in 1 file changed: 17 ins; 9 del; 41 mod
  Patch: https://git.openjdk.org/jdk/pull/12417.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12417/head:pull/12417

PR: https://git.openjdk.org/jdk/pull/12417