RFR: 8255128: linux x86 build failure with libJNIPoint.c

[Jorn Vernee]

Add 32-bit-safe version of jlong <-> casts to libJNIPoint.c

This removes the reported warning.

Note that the _LP64 macro was not being propagated to the benchmark native libraries on Windows. The comment says that this is due to pack200, but since this has been removed [1], it seemed safe to propagate the macro now (backed up by testing).

CC'ing hotspot-runtime since I know some people there were looking forward to having this fixed.

Testing: tier1-3

[1] https://bugs.openjdk.java.net/browse/JDK-8232022

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Commit messages:
 - Add 32-bit safe version of jlong <-> casts to libJNIPoint.c

Changes: https://git.openjdk.java.net/jdk/pull/1017/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1017&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255128
  Stats: 17 lines in 2 files changed: 8 ins; 2 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1017.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1017/head:pull/1017

PR: https://git.openjdk.java.net/jdk/pull/1017