Capture Swift error messages from fatalError, assert, and precondition crashes

[ioannisj]

Description

Problem

Swift crashes from fatalError(), assert(), precondition(), and force unwraps currently appear as SIGTRAP signals without the actual Swift error message. While the stack trace and symbolication work correctly, the specific error context is lost.

For example, a crash from:

fatalError("A critical session has expired")

Shows up as a generic SIGTRAP instead of including the message "A critical session has expired".

References

Swift stores crash messages in the __crash_info Mach-O section of libswiftCore.dylib. At crash time, we can read this section to extract the error message.

Sentry: getsentry/sentry-cocoa#1596
Bugsnag: bugsnag/bugsnag-cocoa#948

[marandaneto]

@ioannisj do we need to update docs or something?