PlotFileUtil: Add Direct Includes

[ax3l]

Summary

Adds the used direct includes to AMReX_PlotFileUtil.H.

Additional background

AMReX-Codes/pyamrex#153

Checklist

The proposed changes:

• fix a bug or incorrect behavior in AMReX
• add new capabilities to AMReX
• changes answers in the test suite to more than roundoff level
• are likely to significantly affect the results of downstream AMReX users
• include documentation in the code and/or rst files, if appropriate

[WeiqunZhang]

Correctness here is subjective. I think all those headers have been indirectly included. Are you seeing real issues?

[ax3l]

Correctness in the sense of include stability:
This will make it long-term stable if transitive headers change.
https://include-what-you-use.org

Changing the label appropriately to cleaning.

[WeiqunZhang]

I tried include-what-you-use in the past. It is too much work to make it happy because we have a lot of build options and we need to add a lot of IWYU pragmas. If we were using it, we would have marked AMReX_MultiFab.H as exporting AMReX_Box.H, AMReX_REAL.H etc.

[ax3l]

I tried include-what-you-use in the past.

Agreed (for the tool). I was more referring to the concept :)

[WeiqunZhang]

I agree with the concept too. :)