RFR: 8375477: CoreUtils support for SA tests should attempt to locate and unzip core files when they have been zipped

[Chris Plummer]

The support for locating zipped (and subsequently unzipped) core files broken when a message in the hs_err file changed, causing CoreUtils.java to not detect the alternate location of the core file. It became broken 2 months ago by the changes for [JDK-8368551](https://bugs.openjdk.org/browse/JDK-8368551). That changed the hotspot message related to the core file location that CoreUtils was searching for:


     if (core_pattern[0] == '|') {
       written = jio_snprintf(buffer, bufferSize,
- ""%s" (or dumping to %s/core.%d)",
+ ""%s" (alternatively, falling back to %s/core.%d)",
                              &core_pattern[1], p, current_process_id());


CoreUtils was checking for "or ", but it needs to check for "alternatively...".

Testing: I checked our CI runs, which used to skip all the SA core files tests on linux-x64 and linux-aarch64, and they are now running the tests and passing properly.

-------------

Commit messages:
 - fix whitespace
 - get rid of unnecessary throws clause
 - fix zipped core file support

Changes: https://git.openjdk.org/jdk/pull/29284/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29284&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8375477
  Stats: 17 lines in 1 file changed: 14 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/29284.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29284/head:pull/29284

PR: https://git.openjdk.org/jdk/pull/29284