Wrong source paths in debug info

[maleadt]

julia> @device_code_ptx raw=true CuArray([1]).+1

	.file	1 "/home/tim/.julia/packages/GPUArrays/8Y80U/src/host/broadcast.jl"
	.file	2 "./int.jl"
	.file	3 "/home/tim/.julia/packages/GPUArrays/8Y80U/src/device/indexing.jl"
	.file	4 "./essentials.jl"
	.file	5 "/home/tim/.julia/packages/LLVM/5DlHM/src/interop/base.jl"
	.file	6 "./broadcast.jl"
	.file	7 "/home/tim/Julia/pkg/CUDA/src/device/array.jl"
	.file	8 "/home/tim/.julia/packages/LLVM/5DlHM/src/interop/pointer.jl"
	.file	9 "./none"

Only package paths seem to be reported correctly. We should try to resolve these to the Julia BINDIR for a better profiling experience.