[compiler] Extend stress mode for lazy source positions

Make stress mode collect source positions for functions that weren't
lazily compiled.

Bug: v8:8510
Change-Id: I632f4b39746a7500ced3b7de9840601c4681856e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1700063
Auto-Submit: Dan Elphick <delphick@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62687}

src/codegen/compiler.cc

@@ -594,6 +594,12 @@ MaybeHandle<SharedFunctionInfo> GenerateUnoptimizedCodeForToplevel(
       return MaybeHandle<SharedFunctionInfo>();
     }
 
+    if (FLAG_stress_lazy_source_positions) {
+      // Collect source positions immediately to try and flush out bytecode
+      // mismatches.
+      SharedFunctionInfo::EnsureSourcePositionsAvailable(isolate, shared_info);
+    }
+
     if (shared_info.is_identical_to(top_level)) {
       // Ensure that the top level function is retained.
       *is_compiled_scope = shared_info->is_compiled_scope();