Swift: auto-flush logs at exit

swift/extractor/main.cpp

@@ -227,7 +227,5 @@ int main(int argc, char** argv, char** envp) {
     observer.markSuccessfullyExtractedFiles();
   }
 
-  codeql::Log::flush();
-
   return frontend_rc;
 }

swift/logging/SwiftLogging.h

@@ -110,6 +110,8 @@ class Log {
     Level level;
   };
 
+  ~Log() { flushImpl(); }
+
   // Flush logs to the designated outputs
   static void flush() { instance().flushImpl(); }
 

swift/xcode-autobuilder/XcodeBuildRunner.cpp

@@ -65,7 +65,6 @@ void buildTarget(Target& target, bool dryRun) {
     if (!exec(argv)) {
       DIAGNOSE_ERROR(build_command_failed, "The detected build command failed (tried {})",
                      absl::StrJoin(argv, " "));
-      codeql::Log::flush();
       exit(1);
     }
   }