[jdk11u-dev] RFR: 8266187: Memory leak in appendBootClassPath()

[Goetz Lindenmaier]

I backport this for parity with 11.0.15-oracle.

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

Commit messages:
 - Backport aa90df6f51940a73f9aa078a32768855c8568034

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/713/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=713&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8266187
  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/713.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/713/head:pull/713

PR: https://git.openjdk.java.net/jdk11u-dev/pull/713