RFR: 8302066: Counter _number_of_nmethods_with_dependencies should be atomic. [v2]

[Robbin Ehn]

> Hi, please consider!
> 
> We increment this counter when holding CodeCache, but loads are holding Compile_lock.
> Lets just make it atomic so we don't need to reason about if there is some race here.
> Also we are trying to avoid 'dirty' reads in the code base. (since in theory it is subject to things like word-tearing)
> 
> Testing tier1 in progress.
> 
> Thanks, Robbin

Robbin Ehn has updated the pull request incrementally with one additional commit since the last revision:

  Spelling

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Changes:
  - all: https://git.openjdk.org/jdk/pull/12470/files
  - new: https://git.openjdk.org/jdk/pull/12470/files/9b2de63e..ca234387

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12470&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12470&range=00-01

  Stats: 3 lines in 2 files changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/12470.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12470/head:pull/12470

PR: https://git.openjdk.org/jdk/pull/12470