RFR: 8216400: improve handling of IOExceptions in JavaCompiler.close() [v3]

[Guoxiong Li]

> Hi all,
> 
> This little patch enhances the code according to the comment by using a simplest way. I found [JDK-8069116](https://bugs.openjdk.java.net/browse/JDK-8069116) is a similar issue. A better way would be appreciated.
> 
> Thank you for taking the time to reivew.
> 
> Best Regards.

Guoxiong Li has updated the pull request incrementally with one additional commit since the last revision:

  Polish.

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1895/files
  - new: https://git.openjdk.java.net/jdk/pull/1895/files/e19b1a22..ae642c2b

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1895&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1895&range=01-02

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1895.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1895/head:pull/1895

PR: https://git.openjdk.java.net/jdk/pull/1895