fix find_package for fftw3 and add arch features

[Neumann-A]

requires: #4782
closes: #3552

[Neumann-A]

TODO: Fix target for RelWithDebInfo linking debug fftw3 libraries

[seanwarren]

Hello, I'm wondering what is the status of this PR?

I have updated this PR to resolve conflicts with master at seanwarren@f0c79e7 .

@Neumann-A Should I create a new PR or would you like to incorporate these changes?

[Neumann-A]

waiting for #5459 until I rebase and force push this branch. The conflicts should be gone then.
I will also remove the last commit because there is a different way to map those in the consuming project, e.g.:

set(CMAKE_MAP_IMPORTED_CONFIG_MINSIZEREL Release)
set(CMAKE_MAP_IMPORTED_CONFIG_RELWITHDEBINFO Release)

[Neumann-A]

AVX/AVX2 ICE related VS Community Feedback

would be nice if someone can tell me what exactly is failing

[Cheney-W]

Here is the test result.

Processing arm64-windows                  465 vs 466
     fftw3                         **regression**                Fail vs Pass

Here are all of the failures logs:
fftw3.zip

[Neumann-A]

Having sse2 as a default for x86 and x64 seems desirable. Is there a syntax to conditionally deactivate features by arch? I thought i saw something in a portfile once for uwp targets but it is not mentioned in the feature docs

[Rastaban]

Currently there is no standard way to conditionally deactivate a feature by arch. Do you feel like having sse2 as default for x86/x64 is a precondition for having this PR merged? If not then am interested in getting this merged and adding an issue for "conditionally deactivate port features for arch that don't support them" and point to this port as a place that would benefit.

[Neumann-A]

Do you feel like having sse2 as default for x86/x64 is a precondition for having this PR merged?

@Rastaban: No just a nice to have feature :)