Bundle 7z[.exe] with libaries/apps

[sloede]

Resolves #681.

[staticfloat]

Do we need to bundle lld as well?

[sloede]

Do we need to bundle lld as well?

Didn't see any issues complaining about missing lld, while 7z is required by Pkg, and it's been complained about just today by two separate parties. I thus went ahead and went with the minimum solution that can help to fix this issue.

Though, as discussed on Slack today, it does not fix the underlying issue of, e.g., MKL_jll being downloaded even if we do not want it.

[codecov]

Codecov Report

Merging #877 (025ce85) into master (254c988) will increase coverage by 0.27%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #877      +/-   ##
==========================================
+ Coverage   84.26%   84.53%   +0.27%     
==========================================
  Files           3        3              
  Lines         801      815      +14     
==========================================
+ Hits          675      689      +14     
  Misses        126      126              

Files	Coverage Δ
src/PackageCompiler.jl	92.72% <100.00%> (+0.15%)	⬆️

[sloede]

@bgeihe @mashu it would be great if you could test this PR to verify that it fixes your respective issues with 7z not being found by Pkg.

[benegee]

Works for me. Praise @sloede !

Sorry, I need to check it again!

[bjarthur]

i tested this PR and it works great! fixes JuliaLinearAlgebra/MKL.jl#137 too

[sloede]

@bjarthur Thanks a lot for verifying! We have conflicting reports from another use (@bgeihe) so I would like to run a few more tests before merging this. However, since for the majority of people this PR seems to work fine, I will create a new release with it probably still within this week.