RFR: 8263190: Update java.io, java.math, and java.text to use instanceof pattern variable

[Brian Goetz]

Looks good!  Glad to see the Amber features finding their way into the 
codebase.

On 3/8/2021 1:53 PM, Patrick Concannon wrote:
> Hi,
>
> Could someone please review my code for updating the code in the `java.io`, `java.math`, and `java.text` packages to make use of the `instanceof` pattern variable?
>
> Kind regards,
> Patrick
>
> -------------
>
> Commit messages:
>   - 8263190: Update java.io, java.math, and java.text to use instanceof pattern variable
>
> Changes: https://git.openjdk.java.net/jdk/pull/2879/files
>   Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2879&range=00
>    Issue: https://bugs.openjdk.java.net/browse/JDK-8263190
>    Stats: 60 lines in 15 files changed: 0 ins; 27 del; 33 mod
>    Patch: https://git.openjdk.java.net/jdk/pull/2879.diff
>    Fetch: git fetch https://git.openjdk.java.net/jdk pull/2879/head:pull/2879
>
> PR: https://git.openjdk.java.net/jdk/pull/2879