Description: The `julia` packages uses local `llvm` version 12 instead of version 11 like the official julia binary. As a (likely) consequence, one optimization is not performed.

This julia file:
```julia
using BenchmarkTools
BenchmarkTools.DEFAULT_PARAMETERS.seconds = 1

function average(collection)
cumsum = 0
for value in collection
cumsum += value
end
cumsum / length(collection)
end

r1 = 1:1_000_000
r2 = 1:2_000_000

println("ranges")
@btime average($r1)
@btime average($r2)
```

Outputs something like the following when using the official `julia` binary:
```
3.168 ns (0 allocations: 0 bytes)
2.675 ns (0 allocations: 0 bytes)
```
The time complexity has been optimized to O(1) with internal use of the triangular number `N * (N + 1) / 2`.

But with the `julia` binary obtained from vanilla `pacman` installation, I get:
```
440.674 μs (0 allocations: 0 bytes)
898.528 μs (0 allocations: 0 bytes)
```
No optimization is made, and time complexity in O(N).


The only difference I noticed is the LLVM version and the `*` next to commit number, here with the `pacman` version:
```
$ /usr/bin/julia
_
_ _ _(_)_ | Documentation: https://docs.julialang.org
(_) | (_) (_) |
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 1.6.2 (2021-07-14)
_/ |\__'_|_|_|\__'_| |
|__/ |

julia> versioninfo()
Julia Version 1.6.2
Commit 1b93d53fc4* (2021-07-14 15:36 UTC)
Platform Info:
OS: Linux (x86_64-pc-linux-gnu)
CPU: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
WORD_SIZE: 64
LIBM: libopenlibm
LLVM: libLLVM-12.0.1 (ORCJIT, skylake)
```

.. and here with the official binary:
```
$ ./julia-1.6.2/bin/julia
_
_ _ _(_)_ | Documentation: https://docs.julialang.org
(_) | (_) (_) |
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 1.6.2 (2021-07-14)
_/ |\__'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |

julia> versioninfo()
Julia Version 1.6.2
Commit 1b93d53fc4 (2021-07-14 15:36 UTC)
Platform Info:
OS: Linux (x86_64-pc-linux-gnu)
CPU: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
WORD_SIZE: 64
LIBM: libopenlibm
LLVM: libLLVM-11.0.1 (ORCJIT, skylake)
```

.. should this be reported here, or at Julia's, or at LLVM?