RFR: JDK-8300242 : Replace NULL with nullptr in share/code/ [v2]

[Johan Sjölen]

> Do the conversion in the share/code/ sub-directory and all of its files.

Johan Sjölen has updated the pull request incrementally with one additional commit since the last revision:

  Fix formatting

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Changes:
  - all: https://git.openjdk.org/jdk/pull/12031/files
  - new: https://git.openjdk.org/jdk/pull/12031/files/252dcd15..1644231d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12031&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12031&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/12031.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12031/head:pull/12031

PR: https://git.openjdk.org/jdk/pull/12031