We need a minimum target of 15.7 or below because of CI, so add a new
`BacktracingDT 6.2` define. This is a bit of a hack for now to
unblock CI upgrades; we can go and clean things up and perhaps
generalise this mechanism later.
rdar://172129091
We can't test the alternate image support for ELF, because that's been
removed in favour of `SymbolLocator`/`SymbolSource`.
Also we must pass `/opt:icf` in the symbolicated backtrace test when
using PDB, otherwise we corrupt the metadata.
Finally fix a mistake in `Utils.swift` where we were crashing if the
environment variable in question wasn't set.
rdar://168454023
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
This is slightly complicated by us currently not supporting this code
on iOS/tvOS/watchOS/visionOS. We should fix that, at which point we
can use the `SwiftStdlib`/`StdlibDeploymentTarget` macros instead.
rdar://164850733
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
Allan Shortlidge
Alastair Houghton
Carl Peto