RFR: 8253572: [windows] CDS archive may fail to open with long file names

[Thomas Stuefe]

Hi all,

there is a long standing bug in the windows version of os::pd_map_memory() which may cause it to fail if the path to
the underlying file is longer than the OS limit. This is mainly of interest for CDS, which uses this functionality to
map in sections of the archive into the memory. This bug may cause the CDS mapping to fail. See also
https://bugs.openjdk.java.net/browse/JDK-8249943.

As with similar cases, the fix is to translate the input file name to a wide character UNC path name and use the
Unicode variant of CreateFile which accepts long path names.

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Commit messages:
 - JDK-8253572

Changes: https://git.openjdk.java.net/jdk/pull/332/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=332&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253572
  Stats: 12 lines in 1 file changed: 10 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/332.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/332/head:pull/332

PR: https://git.openjdk.java.net/jdk/pull/332