Merge pull request #30726 from Microsoft/fix30653

Treat hoisted temp variables as a custom prologue.

src/compiler/transformer.ts

@@ -327,6 +327,8 @@ namespace ts {
                         createVariableDeclarationList(lexicalEnvironmentVariableDeclarations)
                     );
 
+                    setEmitFlags(statement, EmitFlags.CustomPrologue);
+
                     if (!statements) {
                         statements = [statement];
                     }