RFR: JDK-8303606: Memory leaks in Arguments::parse_each_vm_init_arg

[Justin King]

Addresses various memory leaks identified by LSan related to Arguments::parse_each_vm_init_arg.

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Commit messages:
 - Memory leaks in Arguments::parse_each_vm_init_arg

Changes: https://git.openjdk.org/jdk/pull/12867/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12867&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8303606
  Stats: 17 lines in 2 files changed: 10 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/12867.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12867/head:pull/12867

PR: https://git.openjdk.org/jdk/pull/12867