RFR: 8133686: HttpURLConnection.getHeaderFields and URLConnection.getRequestProperties methods return field values in reverse order

[Evan Whelan]

Hi all,

Please review this fix for which corrects the order in which field values are returned from the `HttpURLConnection.getHeaderFields` and `URLConnection.getRequestProperties` methods.

Currently, the implementation of these methods returns the values in reverse. This does not conform with the RFC2616 spec which outlines that the order of these field values should not be changed. 

Thanks,
Evan

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Commit messages:
 - 8133686:  8133686: HttpURLConnection.getHeaderFields and URLConnection.getRequestProperties methods return field values in reverse order v2
 - 8133686: HttpURLConnection.getHeaderFields and URLConnection.getRequestProperties methods return field values in reverse order

Changes: https://git.openjdk.java.net/jdk/pull/2294/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2294&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8133686
  Stats: 418 lines in 7 files changed: 371 ins; 31 del; 16 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2294.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2294/head:pull/2294

PR: https://git.openjdk.java.net/jdk/pull/2294