Due to unfortunate structure packing rules in C, `struct pe_symbol` ends up
being 20 bytes instead of 18. The upshot is that when presented with a PE-COFF
binary that contains symbols (noting that this is actually a spec violation),
the backtracer will crash.
Unfortunately we often generate such binaries. We shouldn’t crash, though, and
the fix is to get the correct size for `struct pe_symbol`.
rdar://171711254
Also, fix two files that managed to use Windows API without
importing `WinSDK` as a result of the leakage caused by including
`windows.h` from `codeview.h`.
rdar://101623384
On-crash backtracing is basically there for 64-bit Windows. It
won't work on 32-bit because of a Swift compiler issue, and there
is a little more work to do yet, but it is now working!
rdar://101623384
This doesn't have a working symbolicator yet, but it does build and
it can obtain a basic backtrace.
It also doesn't include a working `swift-backtrace` program yet.
rdar://101623384
Move the backtracing code into a new Runtime module. This means renaming
the Swift Runtime's CMake target because otherwise there will be a name
clash.
rdar://124913332
