cglobal only shows result on assignment

[ViralBShah]

Trying the example in http://julia.readthedocs.org/en/latest/manual/calling-c-and-fortran-code/#accessing-global-variables gives on mac:

julia> cglobal((:errno, :libc), Int32)
()

but

julia> x = cglobal((:errno, :libc), Int32)
Ptr{Int32} @0x00007fff73f4f280

Is this a bug or does the documentation need updating?

[ViralBShah]

On ARM, the non-assignment case fails, while the one with assignment works.

julia> x = cglobal((:errno, :libc), Int32)
Ptr{Int32} @0xb6feb4d0

julia> cglobal((:errno, :libc), Int32)
julia: cgutils.cpp:1501: jl_value_t* static_constant_instance(llvm::Constant*, jl_value_t*): Assertion `((((jl_value_t*)(jt))->type)==(jl_value_t*)(jl_tuple_type))' failed.

signal (6): Aborted
Aborted (core dumped)

[JeffBezanson]

cc @JuliaBackports

[ivarne]

Backported in d66708f

[tkelman]

can/should this be tested?