Introduces get-lld to fix make full-source-dist USE_BINARYBUILDER=0

[petvana]

This aims to fix #47584. There are no extra sources for lld because it's compiled as part of llvm. In the original PR, I've tested only make USE_BINARYBUILDER=0.

[DilumAluthge]

@ararslan Can you test out this branch?

[ararslan]

Seems not to work:

make[5]: Entering directory '/data/ararslan/julia/deps/scratch/llvm-julia-14.0.6-0/build_Release'
[ 82%] Linking CXX shared library ../../lib/libLLVM-14jl.so
make[5]: Leaving directory '/data/ararslan/julia/deps/scratch/llvm-julia-14.0.6-0/build_Release'
/usr/bin/ld:/data/ararslan/julia/deps/scratch/llvm-julia-14.0.6-0/build_Release/./lib/tools/llvm-shlib/simple_version_script.map:0: syntax error in VERSION script
collect2: error: ld returned 1 exit status
tools/llvm-shlib/CMakeFiles/LLVM.dir/build.make:238: recipe for target 'lib/libLLVM-14jl.so' failed
make[5]: *** [lib/libLLVM-14jl.so] Error 1
make[5]: Leaving directory '/data/ararslan/julia/deps/scratch/llvm-julia-14.0.6-0/build_Release'
CMakeFiles/Makefile2:25594: recipe for target 'tools/llvm-shlib/CMakeFiles/LLVM.dir/all' failed
make[4]: *** [tools/llvm-shlib/CMakeFiles/LLVM.dir/all] Error 2
make[4]: *** Waiting for unfinished jobs....
[ 82%] Built target LLVMExegesisX86
make[4]: Leaving directory '/data/ararslan/julia/deps/scratch/llvm-julia-14.0.6-0/build_Release'
Makefile:155: recipe for target 'all' failed
make[3]: *** [all] Error 2
make[3]: Leaving directory '/data/ararslan/julia/deps/scratch/llvm-julia-14.0.6-0/build_Release'
/data/ararslan/julia/deps/llvm.mk:250: recipe for target 'scratch/llvm-julia-14.0.6-0/build_Release/build-compiled' failed
make[2]: *** [scratch/llvm-julia-14.0.6-0/build_Release/build-compiled] Error 2
make[2]: Leaving directory '/data/ararslan/julia/deps'
Makefile:62: recipe for target 'julia-deps' failed
make[1]: *** [julia-deps] Error 2
make[1]: Leaving directory '/data/ararslan/julia'
Makefile:49: recipe for target '/data/ararslan/julia/doc/_build/html/en/index.html' failed
make: *** [/data/ararslan/julia/doc/_build/html/en/index.html] Error 2

[petvana]

Seems not to work:

Weird. It was successful locally on Ubuntu 20.04. Moreover, I'm not even sure it's related to lld ...

[gbaraldi]

I've had issues with our from source LLVM build in one computer so we might want to find out what is going on there

[petvana]

Can we merge this PR? It solves at least the missing get-lld target.