Redo generated files to eliminate patching after configure

[paulmon]

If you look at the second commit you can see what is patched. Some of these are just carried forward from the PR I started from.

[paulmon]

The configured headers don't need to be patched for x86/x64 builds to work all of the ctypes tests to pass for x86/x84 both debug and release.

Also updated configure.host to match libffi/master so that configure will work for Win32.

It should be possible with these changes to take a new snapshot and then run configure_headers.bat and check in in the new configured headers.

Note that configure_headers.bat requires cygwin to work, is currently hardcoded to c:\cygwin\bin\sh.exe as the cygwin shell host. Everything else is relative to the location of configure_headers.bat

[zooba]

@paulmon Is the configure_headers.bat file yours? If so, can you move it back to the main repo under PCbuild (where you deleted it from). We typically delete the entire contents of these directories before dropping in updated versions, and needing to preserve files makes that a real pain (similarly for keeping our docs in the main repo rather than in this one).

Also, please make the paths in the batch file env variables (and only set the default if not defined <VAR>). That will make it much easier to run it from different machines.

[paulmon]

Yes. I have moved it back and made it configurable through environment variables.