RFR: 8278753: Runtime crashes with access violation during JNI_CreateJavaVM call

[Yumin Qi]

Please review,
  When jlink with --compress=2, zip is used to compress the files while doing copy. The user case failed to load zip.dll, since zip.dll is not set in PATH. This failure is after we get NULL from GetModuleHandle("zip.dll"), then do LoadLibrary("zip.dll") will have same result.
  The fix is calling load_zip_library of ClassLoader first --- if zip library already loaded just return the cached handle for following usage, if not, load zip library and cached the handle.

  Tests: tier1,4,7 in test
   Manually tested user case, and checked output of jimage list <modules> for jlinked files using --compress=2.

Thanks
Yumin

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Commit messages:
 - 8278753: Runtime crashes with access violation during JNI_CreateJavaVM call

Changes: https://git.openjdk.java.net/jdk/pull/7206/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7206&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8278753
  Stats: 49 lines in 6 files changed: 18 ins; 14 del; 17 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7206.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7206/head:pull/7206

PR: https://git.openjdk.java.net/jdk/pull/7206