RFR: 8302685: Some javac unit tests aren't reliably closing open files

[Joe Darcy]

On Thu, 16 Feb 2023 21:32:44 GMT, Archie L. Cobbs <duke at openjdk.org> wrote:

> Some javac unit tests aren't reliably closing open files. Many were written prior to (or without utilizing) try-with-resources.
> 
> Leaving files and other resources open can cause problems during automated builds, etc.
> 
> This patch updates these tests to use try-with-resource.
> 
> Side note: there is at least one unit test that intentionally leaves a file open - `diags/examples/ProcUnclosedTypeFiles/processors/AnnoProc.java`.

Looks fine; however, another engineer who works in the langtools area should look over the changes too.

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Marked as reviewed by darcy (Reviewer).

PR: https://git.openjdk.org/jdk/pull/12609