Use `task_read_for_pid()` rather than having the crashing program pass its
own task port through. This opts us in to additional OS security measures
surrounding the use of this call.
rdar://107362003
This is needed because we can't include `<stdint.h>` or `<inttypes.h>`
on Darwin without dragging in the Darwin package.
The previous solution was some icky `#define` nonsense. This is
better.
rdar://106234311
Adds a new swift_Backtracing library, with a corresponding _Backtracing
module, to the build. Also add some tests.
This is not public API at this point, but will be used by the external
backtracing program, `swift-backtrace`.
rdar://104336548
In order for the runtime PR to work as a separate PR, it does need a little
bit of code in the `_SwiftBacktracing.h` header in SwiftShims.
rdar://105391747
