RFR: 6633375: FileOutputStream_md.c should be merged into FileOutputStream.c

[Brian Burkhalter]

Merge identical Unix and Windows versions of FileOutputStream_md.c into single, common FileOutputStream.c.

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Commit messages:
 - 6633375: FileOutputStream_md.c should be merged into FileOutputStream.c

Changes: https://git.openjdk.java.net/jdk/pull/4589/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4589&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-6633375
  Stats: 77 lines in 2 files changed: 0 ins; 74 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4589.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4589/head:pull/4589

PR: https://git.openjdk.java.net/jdk/pull/4589