RFR: 8223188: Removed unnecessary #ifdef __cplusplus from .cpp sources [v2]

[Alexey Semenyuk]

> Remove needless `#ifdef __cplusplus` from .cpp sources

Alexey Semenyuk has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:

  8223188: Removed unnecessary #ifdef __cplusplus from .cpp sources

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2466/files
  - new: https://git.openjdk.java.net/jdk/pull/2466/files/e9241319..bd1c3af5

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2466&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2466&range=00-01

  Stats: 0 lines in 0 files changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2466.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2466/head:pull/2466

PR: https://git.openjdk.java.net/jdk/pull/2466