[jdk8u-dev] RFR: 8274893: Update java.desktop classes to use try-with-resources [v3]

[Timofei Pushkin]

> Backport of [JDK-8274893](https://bugs.openjdk.org/browse/JDK-8274893) for parity with Oracle's JDK 8u461.
> 
> The first commit is a cherry-pick of the backport to JDK 11 with conflicts unresolved, the second resolves the conflicts, the rest resolve issues uncaught by git.
> 
> Resolved:
> - `jdk/src/share/classes/com/sun/java/swing/plaf/gtk/Metacity.java`
>   - Missing JDK-8271456: `"ISO-8859-1"` string is used instead of `ISO_8859_1` enum constant
>   - Missing JDK-8041679: `StringBuffer` is used instead of `StringBuilder`
> - `jdk/src/share/classes/javax/swing/text/html/HTMLEditorKit.java`
>   - Missing JDK-8271456: `"ISO-8859-1"` string is used instead of `ISO_8859_1` enum constant
> - `jdk/src/share/classes/com/sun/media/sound/StandardMidiFileWriter.java`
>   - Missing JDK-8143909: no `Objects.requireNonNull(...)` in this version
> - `jdk/src/solaris/classes/sun/awt/motif/MFontConfiguration.java`
>   - Missing JDK-8054834: imports from `sun.font` package are still needed in this file
> - `jdk/src/share/classes/com/sun/imageio/plugins/png/PNGImageReader.java`
>   - Missing JDK-8080835: use `IOUtils.readAllBytes(InputStream is)` instead of the missing `InputStream.readAllBytes()`
> - Missing JDK-7196163: try-with-resources cannot be used with pre-existing variables — fell back to try-finally in such cases
> 
> Testing: GitHub CI, `jdk_imageio` test group locally (headless linux/arm64)

Timofei Pushkin has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains one additional commit since the last revision:

  8274893: Update java.desktop classes to use try-with-resources
  
  Backport-of: 70c6df6be431fe11c5441986ed04040f9ec3b750

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

Changes:
  - all: https://git.openjdk.org/jdk8u-dev/pull/686/files
  - new: https://git.openjdk.org/jdk8u-dev/pull/686/files/3fd18e4f..fd9a0235

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=686&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=686&range=01-02

  Stats: 182448 lines in 429 files changed: 174839 ins; 6627 del; 982 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/686.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/686/head:pull/686

PR: https://git.openjdk.org/jdk8u-dev/pull/686