Adding restrict_platform support for FPRIME_HAS_XYZ flags

[LeStarch]

Related Issue(s)
Has Unit Tests (y/n)
Documentation Included (y/n)

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Change Description

restrict_platforms is a nice feature to prevent code from attempting to build on platforms that do not support a given module. However, ongoing work in the VxWorks area has shown that some platforms support features (e.g. SOCKETS) without the platform (e.g. VxWorks) in the restrict-to list nor the restrict-to pseudo list (e.g. Posix).

This implies that restrict_platforms should also support feature sets. This PR allows syntax like the following:

restrict_plarforms(SOCKETS)

and allows platform developers to set the corresponding flag

set(FPRIME_HAS_SOCKETS)

This will allow platforms to pass for code built on a feature set that isn't as clear cut as platform (e.g. Linux), toolchain (e.g. arm-linux), or Posix sudo-os.

Extending to the future, this could be used to allow code that is built on platforms with pre-supplied libraries installed (e.g. the platform and cross-compiler supply opencv). This could be represented as FPRIME_HAS_OPENCV.

Note: OPENCV here is a hypothetical example, and is not implemented in this PR.

[LeStarch]

@thomas-bc and @kevin-f-ortega this PR is needed to build VxWorks w/ sockets when the VxWorks posix support layer is turned off.

[kevin-f-ortega]

Looks good to me, thanks! Just one question