[Backtracing] Added JSON crash log option.

Also made it so the `sanitize` option causes the crash logs to not
include memory dumps.

Fixes #71057
rdar://121430255

Author: al45tair

stdlib/public/RuntimeModule/Backtrace.swift

@@ -194,6 +194,30 @@ public struct Backtrace: CustomStringConvertible, Sendable {
           return "..."
       }
     }
+
+    /// A JSON description of this frame, less the surrounding braces.
+    /// This is useful if you want to add extra information.
+    @_spi(Internal)
+    public var jsonBody: String {
+      switch self {
+        case let .programCounter(addr):
+          return "\"kind\": \"programCounter\", \"address\": \"\(addr)\""
+        case let .returnAddress(addr):
+          return "\"kind\": \"returnAddress\", \"address\": \"\(addr)\""
+        case let .asyncResumePoint(addr):
+          return "\"kind\": \"asyncResumePoint\", \"address\": \"\(addr)\""
+        case let .omittedFrames(count):
+          return "\"kind\": \"omittedFrames\", \"count\": \(count)"
+        case .truncated:
+          return "\"kind\": \"truncated\""
+      }
+    }
+
+    /// A JSON description of this frame.
+    @_spi(Internal)
+    public var jsonDescription: String {
+      return "{ \(jsonBody) }"
+    }
   }
 
   /// Represents an image loaded in the process's address space

stdlib/public/RuntimeModule/BacktraceFormatter.swift

@@ -416,7 +416,8 @@ private func untabify(_ s: String, tabWidth: Int = 8) -> String {
 /// @param path  The path to sanitize.
 ///
 /// @returns A string containing the sanitized path.
-private func sanitizePath(_ path: String) -> String {
+@_spi(Formatting)
+public func sanitizePath(_ path: String) -> String {
   #if os(macOS)
   return CRCopySanitizedPath(path,
                              kCRSanitizePathGlobAllTypes

stdlib/public/libexec/swift-backtrace/CMakeLists.txt

@@ -33,6 +33,7 @@ set(BACKTRACING_COMPILE_FLAGS
 set(BACKTRACING_SOURCES
   main.swift
   AnsiColor.swift
+  JSON.swift
   TargetMacOS.swift
   TargetLinux.swift
   Themes.swift