Add temporary LLVM C API for accessing source location information.

[maleadt]

For CUDAnative, in order to generate better error messages when we encounter invalid LLVM IR.
To be removed once we have D46627.

e.g.

using CUDAnative

foo() = nonexisting
bar() = foo()

julia> @cuda bar()
ERROR: could not compile bar() for GPU; unsupported LLVM IR

Reason: unsupported call to the Julia runtime (jl_get_binding_or_error)
Stacktrace:
 [1] foo at REPL[13]:1
 [2] bar at REPL[14]:1

Try inspecting generated code with the @device_code_... macros
Stacktrace:
 [1] #compiler_error#43 at /home/tbesard/Julia/CUDAnative/src/jit.jl:33

Ref maleadt/LLVM.jl@2b282be JuliaGPU/CUDAnative.jl@694eebe