Base.find_source_file fails in out-of-tree builds

[mortenpi]

E.g. something like Base.find_source_file("array.jl") would normally return something like /home/mortenpi/Julia/julia-oot-test/usr/bin/../share/julia/base/array.jl, but in an out-of-tree build (no make install) it simply returns a nothing. Should it perhaps still return a path to the original source directory even in that case?

[RalphAS]

Some of the files in base are generated, i.e. are only in the build tree, which complicates things. A fix for this issue is to symlink (or copy where necessary) the content of the distribution base into $BUILDROOT/usr/share/julia/base.