RFR: 8136895: Writer not closed with disk full error, file resource leaked [v2]

[Brian Burkhalter]

> In`StreamEncoder::implClose`, move `flushLeftoverChar()` inside the `try` block and the closing of the underlying stream inside the `finally` block.

Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:

  8136895: Do not swallow exceptions in StreamEncoder::implFlush; add test for OutputStreamWriter; rename test for Channels::newWriter"

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Changes:
  - all: https://git.openjdk.org/jdk/pull/13503/files
  - new: https://git.openjdk.org/jdk/pull/13503/files/30f26153..181a943a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13503&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13503&range=00-01

  Stats: 100 lines in 3 files changed: 97 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/13503.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13503/head:pull/13503

PR: https://git.openjdk.org/jdk/pull/13503