Compiling with NVHPC

[Iximiel]

Description

In this PR I will set up some modifications to the code in order to make possible to compile all plumed with nvhpc v24.3.

As now is a work in progress, I do not know if the CI will even start and some regtests are failing on my pc, the PR is set up to check easily if the modifications do not break other compilers against the master branch.

Target release

I would like my code to appear in release 2.10

Type of contribution

• changes to code or doc authored by PLUMED developers, or additions of code in the core or within the default modules
• changes to a module not authored by you
• new module contribution or edit of a module authored by you

Copyright

• I agree to transfer the copyright of the code I have written to the PLUMED developers or to the author of the code I am modifying.

• the module I added or modified contains a COPYRIGHT file with the correct license information. Code should be released under an open source license. I also used the command cd src && ./header.sh mymodulename in order to make sure the headers of the module are correct.

Tests

• I added a new regtest or modified an existing regtest to validate my changes.
• I verified that all regtests are passed successfully on GitHub Actions.

[GiovanniBussi]

I would avoid setting a macro PLMDAUTO in a .h file which could be included somewhere else. I think this is fine also with gcc:

// nvc++ cannot deduce the type correctly
const typename C::value_type & top() const { return *fwdIt; }

Also, I recently noticed this also with icpc installed on SISSA modules. So maybe it is a widespread bug

[GiovanniBussi]

I would leave a comment like
// nvc++ and icpc do not deduce the type

otherwise sooner or later we will "fix it" back to "auto"