RFR: JDK-8298084: Memory leak in Method::build_profiling_method_data

[Justin King]

Resolve memory leak related to `MethodData::_extra_data_lock` in `Method::build_profiling_method_data` by defining `MethodData::release_C_heap_structures` and calling it where appropriate before deallocating `MethodData`.

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Commit messages:
 - Memory leak in MethodData

Changes: https://git.openjdk.org/jdk/pull/11526/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11526&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8298084
  Stats: 17 lines in 3 files changed: 11 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/11526.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11526/head:pull/11526

PR: https://git.openjdk.org/jdk/pull/11526