backends/ninja: generate symlink aliases for rust/cs/swift libraries too

[eli-schwartz]

Basically the last thing we did during target processing was to generate shlib symlinks for e.g. libfoo.so -> libfoo.so.1.

In some cases we would dispatch to another function and return early, though, which meant we never got far enough to generate the symlinks. This then led to breakage when people tried to compile against libfoo.so

This surely breaks -uninstalled.pc usage, and also caused problems in rust-lang/rust#90260

[codecov]

Codecov Report

Merging #9920 (5d932f3) into master (0185f2e) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #9920      +/-   ##
==========================================
- Coverage   67.79%   67.78%   -0.02%     
==========================================
  Files         402      402              
  Lines       85522    85522              
  Branches    18811    18811              
==========================================
- Hits        57981    57968      -13     
- Misses      23050    23060      +10     
- Partials     4491     4494       +3     

Impacted Files	Coverage Δ
mesonbuild/backend/ninjabackend.py	86.27% <100.00%> (ø)
mesonbuild/scripts/vcstagger.py	87.50% <0.00%> (-4.17%)	⬇️
mesonbuild/dependencies/ui.py	68.45% <0.00%> (-1.35%)	⬇️
mesonbuild/dependencies/dev.py	67.16% <0.00%> (-1.20%)	⬇️
mesonbuild/minstall.py	67.32% <0.00%> (-0.73%)	⬇️
mesonbuild/dependencies/base.py	85.07% <0.00%> (-0.60%)	⬇️
backend/ninjabackend.py	73.26% <0.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 689504b...5d932f3. Read the comment docs.