[shims] Remove all remaining overlay shims modules except XCTest and Dispatch

[lorentey]

Now that we don't have unmaintained versions of the Foundation/CoreFoundation/ObjectiveC/Dispatch overlays within the Swift repository, we don't need to keep installing their obsolete shims modules in toolchains.

Except for XCTest, which is still used by the real XCTest overlay in Xcode 12, and Dispatch which is still being used by swift-corelibs-dispatch on Linux. (We can remove these later.)

rdar://60248672&60248637&60246200

[lorentey]

@swift-ci test

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 769b0802f09e82916d267cacb6d92fbf9ce19ad0

[lorentey]

15:38:13 
/home/buildnode/jenkins/workspace/swift-PR-Linux/branch-main/swift-corelibs-libdispatch/src/swift/Block.swift:14:8: error: no such module '_SwiftDispatchOverlayShims'
15:38:13 import _SwiftDispatchOverlayShims
15:38:13        ^
15:38:13 ninja: build stopped: subcommand failed.

Well that will need fixing.

[lorentey]

@swift-ci test

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - a072d2c

[lorentey]

20:23:09 
<unknown>:0: error: module file '/home/buildnode/jenkins/workspace/swift-PR-Linux/branch-main/buildbot_linux/swiftpm-linux-x86_64/x86_64-unknown-linux-gnu/swift-driver/module-cache/3UDNGN3MS1MO/CDispatch-2JBEV7J094K3O.pcm' is out of date and needs to be rebuilt: signature mismatch
20:23:09 <unknown>:0: note: imported by module '_SwiftDispatchOverlayShims' in '/home/buildnode/jenkins/workspace/swift-PR-Linux/branch-main/buildbot_linux/swiftpm-linux-x86_64/x86_64-unknown-linux-gnu/swift-driver/module-cache/3UDNGN3MS1MO/_SwiftDispatchOverlayShims-R85U541UTPA8.pcm'
20:23:09 <unknown>:0: error: missing required module '_SwiftDispatchOverlayShims'
20:23:09 ninja: build stopped: subcommand failed.

Hm, maybe we need a clean build

[lorentey]

@swift-ci please clean test linux platform

[lorentey]

The windows build timed out. 🤔

Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..Build timed out (after 60 minutes). Marking the build as aborted.

[lorentey]

@swift-ci test windows platform