RFR: 8281717: Cover logout method for several LoginModule [v3]

[Sibabrata Sahoo]

> Added coverage to logout method.

Sibabrata Sahoo has updated the pull request incrementally with one additional commit since the last revision:

  Update AllPlatforms.java
  
  Updated exception handling to ignore the case where the running platform doesn't match the test case. In that case required native library loading will fail.

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7940/files
  - new: https://git.openjdk.java.net/jdk/pull/7940/files/13a999b0..b7e3bc04

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7940&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7940&range=01-02

  Stats: 5 lines in 1 file changed: 2 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7940.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7940/head:pull/7940

PR: https://git.openjdk.java.net/jdk/pull/7940