RFR: 8324679: Replace NULL with nullptr in HotSpot .ad files [v3]

[Coleen Phillimore]

> This is a straightforward mechanical (sed) replacement of NULL with nullptr.  One string was adjusted to not say nullptr ptr.  nullptr makes sense in the comments so I didn't change them.
> 
> Tested with tier1 Oracle platforms and build test with linux-x64-zero,linux-x64-zero-debug,linux-s390x-open,linux-arm32-debug,linux-ppc64le-debug,linux-riscv64-debug

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  Update src/hotspot/cpu/arm/arm.ad

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Changes:
  - all: https://git.openjdk.org/jdk/pull/17658/files
  - new: https://git.openjdk.org/jdk/pull/17658/files/019b6027..4024e5ff

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17658&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17658&range=01-02

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/17658.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17658/head:pull/17658

PR: https://git.openjdk.org/jdk/pull/17658