Bring back registry stub :(

src/registry-stub/Makefile

@@ -0,0 +1,2 @@
+api-ms-win-core-registry-l1-1-0.dll: api-ms-win-core-registry-l1-1-0.c
+	gcc -o $@ -fPIC -shared -Wall $^

src/registry-stub/README.md

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+This stubs the `RegCloseKey` function provided on Windows by
+`api-ms-win-core-registry-l1-1-0.dll`.
+
+Without this DLL in the library path, the following exception is
+thrown upon shutdown of PowerShell. While I do not like hiding this
+error, it is neccesary for the rest of PowerShell to shutdown
+properly, and release its file descriptors. Otherwise the shell will
+mess up Bash, and it needs to be reset.
+
+This must be removed as soon as it can be addressed in a better way.
+
+```
+Unhandled Exception: System.DllNotFoundException: Unable to load DLL 'api-ms-win-core-registry-l1-1-0.dll': The specified module could not be found.
+ (Exception from HRESULT: 0x8007007E)
+   at Interop.mincore.RegCloseKey(IntPtr hKey)
+   at Microsoft.Win32.SafeHandles.SafeRegistryHandle.ReleaseHandle()
+   at System.Runtime.InteropServices.SafeHandle.InternalFinalize()
+   at System.Runtime.InteropServices.SafeHandle.Dispose(Boolean disposing)
+   at System.Runtime.InteropServices.SafeHandle.Finalize()
+```

src/registry-stub/api-ms-win-core-registry-l1-1-0.c

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+#include <stdint.h>
+
+int32_t RegCloseKey(void* handle)
+{
+    return 0;
+}