Capitalization of DevNull

[yurivish]

DevNull is proper case while STDOUT is upper case. Since we generally only use CamelCase for types and modules, this should perhaps be changed to something like DEVNULL.

(cc @nalimilan)

[yurivish]

Bump. This is a small but backwards-incompatible name consistency change. Should it be done for 1.0?

[nalimilan]

Let's hear what triage thinks about this (will happen tomorrow).

[ararslan]

I think we should do this.

[ararslan]

As an aside, the Julia Vim definitions used to highlight DevNull as a type, likely because it's cased like it is one.

[JeffBezanson]

From triage: there is some significant support for making these all lowercase --- stdout, stdin, stderr, devnull --- which follows C more. It also matches the keyword argument names to pipeline, e.g. pipeline(cmd, stderr=stdout).

[nalimilan]

But don't we follow the convention that constants use uppercase?

[mbauman]

It turns out neither STDOUT nor STDIN are constants. DevNull, however, is.

[ararslan]

But don't we follow the convention that constants use uppercase?

It was pointed out that we don't always: Inf, NaN, missing, nothing, etc. (That said, I'm still in favor of this particular change.)

[JeffBezanson]

I like lowercasing all of these: stdin, stdout, stderr, devnull. @Keno points out that devnull comes from /dev/null, which is lowercase.

[StefanKarpinski]

Also, stdin, stdout and stderr are all lowercase in C (upper casing then comes from Perl/Ruby).

[StefanKarpinski]

Triage votes for lowercasing all of these with a dissenting vote from @ararslan.

[ararslan]

I've adjusted #25959 per triage consensus.