RFR: Fix simple warnings [v2]

[Jorn Vernee]

On Sun, 7 Apr 2024 16:51:18 GMT, Nir Lisker <nlisker at openjdk.org> wrote:

>> Fixes for warnings:
>> 
>> * Missing `@Override` annotations
>> * Unnecessary code (casts and semicolons)
>> * Unused imports
>> 
>> There are more complicated warnings that should be looked at separately like resource leaks, potential null access, and unused variables.
>
> Nir Lisker has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add newline

Err, looks like one of the changes here results in a compilation failure (and I accidentally tested the wrong branch before approving :/)


> Task :compileJava FAILED
.\src\main\java\org\openjdk\jextract\impl\Utils.java:240: error: not a statement
                    yield double.class;
                    ^
.\src\main\java\org\openjdk\jextract\impl\Utils.java:240: error: ';' expected
                    yield double.class;
                         ^
.\src\main\java\org\openjdk\jextract\impl\Utils.java:240: error: not a statement
                    yield double.class;
                                ^
Note: Some input files use preview features of Java SE 22.
Note: Recompile with -Xlint:preview for details.
3 errors

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

PR Comment: https://git.openjdk.org/jextract/pull/229#issuecomment-2041606913