This commit renames the functions in conpty.lib to Conpty* so that they
can be explicitly linked and introduces a header so they can be located.
It also updates the DEF for conpty.dll to reexport them with their
original names.
The crux of the issue here is that TerminalConnection is consuming the
_import_ symbols for the *PseudoConsole family of APIs, which simply
cannot be supplanted by a static library.
Avenues explored: * Exporting __imp_x from the static library to get all
up in kernel32's business. * Using /ALTERNATENAME:__imp_X=StaticX. It
turns out ALTERNATENAME is only consulted when the symbol isn't found
through traditional means.
This, renaming them, is the straightest path forward.
Fixes#3553.
This commit deletes ConhostConnection and replaces it with
ConptyConnection. The ConptyConnection uses CreatePseudoConsole and
depends on winconpty to override the one from kernel32.
* winconpty must be packageable, so I've added GetPackagingOutputs.
* To validate this, I added conpty.dll to the MSIX regression script.
* I moved the code from conpty-universal that deals with environment
strings into the types library.
This puts us in a way better place to implement #2563, as we can now
separately detect a failure to launch a pseudoconsole, a failure to
CreateProcess, and an unexpected termination of the launched process.
Fixes#1131.
