Multiple BuildConfigurations for one platform

[Maplesoft-fmigroup]

Section 2.4.10 of the spec states that:
For each 'platform' there can only be one matching <BuildConfiguration>
This is problematic if a SourceCode FMU exporter wants to provide separate configurations for different compilers that require different compiler flags.

[chrbertsch]

The 'platform' refers to the platform tuple definition in https://fmi-standard.org/docs/3.0-dev/#structure-of-zip.
There for statically linked librares it is possible to to extend '-' with an ABI-String.
Does it make sense to allow a similar extension for different compilers for the build-configuration?
Is is possible to standarize such an extension string (using the ABI string?) ?
Or could the exporter just choose an any explaining string? (e.g. VisualC, gcc, clang++? Or would it be necessary to include version information for the compiler?)

[PTaeuberDS]

This is somehow related to #1305.
When using "any explaining string" for compiler it might be hard for the importer to identify if the compiler matches one of the available compilers.

[andreas-junghanns]

Web Design Meeting:
"Platform" string could contain the compiler string.
TorstenS: We could allow multiple build configurations.
Kaska: We would have to extend the standardized list of compiler names.
Pierre: This is not winnable: not even "gcc" is clearly defined.
Andreas: If the importer needs to know: the user needs to decide which to pick.
Andreas: Exporters should be able to supply as many configurations per platform as possible...
Kaska: On Windows, we want to provide at least for tcc, msvc, On Linux and Mac: Gcc and tcc.

Matthias: Now we have one build configuration per platform. Can´t we do that with the source file sets?
TorstenS: The idea was that you need all source file sets for one FMU.
Pierre+TorstenB: This needs to be clarified.
Matthias: This needs clarification for sure.

Christian: Should we standardize the build description names?
TorstenS: You should pick descriptive names, but there cannot be really a standard because there are too many different versions.

TorstenS: I will make a PR.

[andreas-junghanns]

• Relax requirement on uniqueness of the platform (multiple entries allowed)
• Add clarification for what to compile to make a complete FMU: All SourceFileSets must be compiled within one BuildConfiguration
• Non-normative: Explain what is enabled by this mechanism