Temporarily turn on -Werror StrictMemorySafety.

Author: tshortli

stdlib/cmake/modules/SwiftSource.cmake

@@ -643,6 +643,9 @@ function(_compile_swift_files
 
   list(APPEND swift_flags "-enable-upcoming-feature" "MemberImportVisibility")
 
+  # Require all StrictMemorySafety diagnostics to be addressed.
+  list(APPEND swift_flags "-Werror" "StrictMemorySafety")
+
   if (SWIFT_STDLIB_ENABLE_STRICT_CONCURRENCY_COMPLETE)
     list(APPEND swift_flags "-strict-concurrency=complete")
   endif()