Revert "Merge pull request #81840 from compnerd/aliases"

[MaxDesiatov]

This reverts commit 33a324e, reversing changes made to 0afeafa due to a regression:

$ printf "import var Darwin.stderr\n" | /Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2025-06-09-a.xctoolchain/usr/bin/swiftc -typecheck - -sdk $(xcrun --show-sdk-path)
<stdin>:1:12: error: ambiguous name 'stderr' in module 'Darwin'
1 | import var Darwin.stderr
  |            `- error: ambiguous name 'stderr' in module 'Darwin'
2 |

_stdio.stderr:2:12: note: found this candidate
1 | @available(macOS 10.9, iOS 7.0, watchOS 2.0, tvOS 9.0, visionOS 1.0, *)
2 | public var stderr: UnsafeMutablePointer<FILE> { get set }
  |            `- note: found this candidate

_stdio.stderr:1:12: note: found this candidate
1 | public var stderr: UnsafeMutablePointer<FILE> { get set }
  |            `- note: found this candidate

# Conflicts:
#	test/ClangImporter/Inputs/custom-modules/module.modulemap

[MaxDesiatov]

@swift-ci smoke test

[compnerd]

I’m going to just add an exclusion for Darwin, there’s no good fix here that I can do - this requires changing the Darwin overlays.

[compnerd]

I wonder if @hnrklssn has any suggestions to avoid the exclusion of the Darwin module.

[compnerd]

#82213 should at least get this workarounded

[al45tair]

Let's do #82213 if we can, and then worry about fixing that later, rather than reverting everything.

[hnrklssn]

I wonder if @hnrklssn has any suggestions to avoid the exclusion of the Darwin module.

The only thing I can think of would be if @_disfavoredOverload works for variables, but it's a bit of an ugly hack, so if those 3 defines in stdio are the only ones we have to special-case to make this work, I'd rather temporarily do that until Darwin is updated.