Merge pull request swift-server#49 from weissi/jw-other-platforms

forgot other platforms

Merge pull request swift-server#48 from weissi/jw-signals

allow other signals

recent changes to support windows broke macos (swift-server#44)

motivation: unbreak macos

changes: make _stdlib_demangleName only available on macOS and Windows where it is fully supported

README: add acknowledgement for Windows port (swift-server#43)

Merge pull request swift-server#35 from weissi/jw-error

better distinguish mmap errors & print errno

add testing (swift-server#26)

motivation: make sure library works as expected

changes:
* add a Sample target we can use for testing
* add a test to make sure backtraces are printed as expected
* make docker tests use a release version for a more realistic tests
* update linux test generation script to work with release builds

feat: cross-compilation (swift-server#17)

feat: add Backtrace.print() function (swift-server#15)

doc: update README as post-mortem symbolication is no longer needed

Merge pull request swift-server#3 from ianpartridge/swift-4.2

feat: Support Swift 4.2