RFR: 8257858: [macOS]: Remove JNF dependency from libosxsecurity/KeystoreImpl.m [v2]

[Weijun Wang]

> This fix covers both
> 
> - [[macOS]: Remove JNF dependency from libosxsecurity/KeystoreImpl.m](https://bugs.openjdk.java.net/browse/JDK-8257858)
> - [[macOS]: Remove JNF dependency from libosxkrb5/SCDynamicStoreConfig.m](https://bugs.openjdk.java.net/browse/JDK-8257860)

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  same behavior as before -- empty realm map

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1845/files
  - new: https://git.openjdk.java.net/jdk/pull/1845/files/cb02503f..b0ee18a8

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1845&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1845&range=00-01

  Stats: 4 lines in 1 file changed: 1 ins; 1 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1845.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1845/head:pull/1845

PR: https://git.openjdk.java.net/jdk/pull/1845