Enable better runtime failure messages
The implementation was done quite a while ago.
Now, that we have support in lldb (https://github.com/apple/llvm-project/pull/773), we can enable it by default in the compiler.
LLDB now shows the runtime failure reason, for example:
* thread #1, queue = 'com.apple.main-thread', stop reason = Swift runtime failure: arithmetic overflow
frame #1: 0x0000000100000f0d a.out`testit(a=127) at trap_message.swift:4
1
2 @inline(never)
3 func testit(_ a: Int8) -> Int8 {
-> 4 return a + 1
5 }
6
For details, see https://github.com/apple/swift/pull/25978
rdar://problem/51278690
