Walk-around a dangling pointer issue

This issue happens in B&I and only reproduces in release builds. It suggests that
we should set up testing swift-driver with ASAN turned on.

rdar://71942829

Author: nkcsgexi

Sources/SwiftDriver/Incremental Compilation/BuildRecord.swift

@@ -135,19 +135,17 @@ public extension BuildRecord {
 extension BuildRecord {
   /// Create a new buildRecord for writing
   init(jobs: [Job],
-       finishedJobResults: [Job: ProcessResult],
+       finishedJobResults: [JobResult],
        skippedInputs: Set<TypedVirtualPath>?,
        compilationInputModificationDates: [TypedVirtualPath: Date],
        actualSwiftVersion: String,
        argsHash: String,
        timeBeforeFirstJob: Date
   ) {
-    let jobResultsByInput = Dictionary(
-      uniqueKeysWithValues:
-        finishedJobResults.flatMap { job, result in
-          job.primaryInputs.map { ($0, result)  }
-        }
-    )
+    let jobResultsByInput = Dictionary(uniqueKeysWithValues:
+      finishedJobResults.flatMap { entry in
+        entry.j.primaryInputs.map { ($0, entry.result) }
+    })
     let inputInfosArray = compilationInputModificationDates
       .map { input, modDate -> (VirtualPath, InputInfo) in
         let status = InputInfo.Status(  wasSkipped: skippedInputs?.contains(input),

Sources/SwiftDriver/Incremental Compilation/BuildRecordInfo.swift

@@ -14,6 +14,15 @@ import Foundation
 import TSCBasic
 import SwiftOptions
 
+struct JobResult {
+  let j: Job
+  let result: ProcessResult
+  init(_ j: Job, _ result: ProcessResult) {
+    self.j = j
+    self.result = result
+  }
+}
+
 /// Holds information required to read and write the build record (aka compilation record)
 /// This info is always written, but only read for incremental compilation.
  class BuildRecordInfo {
@@ -25,7 +34,7 @@ import SwiftOptions
   let diagnosticEngine: DiagnosticsEngine
   let compilationInputModificationDates: [TypedVirtualPath: Date]
 
-  var finishedJobResults  = [Job: ProcessResult]()
+  var finishedJobResults  = [JobResult]()
 
   init?(
     actualSwiftVersion: String,
@@ -175,8 +184,6 @@ import SwiftOptions
 
   func jobFinished(job: Job, result: ProcessResult) {
     // REDUNDANT?
-    if let _ = finishedJobResults.updateValue(result, forKey: job) {
-      fatalError("job finished twice?!")
-    }
+    finishedJobResults.append(JobResult(job, result))
   }
 }