Create truly unique names for tagged template strings.

src/compiler/transformers/es2015.ts

@@ -3676,7 +3676,8 @@ namespace ts {
             // Do not do this in the global scope, as any variable we currently generate could conflict with
             // variables from outside of the current compilation. In the future, we can revisit this behavior.
             if (isExternalModule(currentSourceFile)) {
-                const tempVar = createTempVariable(recordTaggedTemplateString);
+                const tempVar = createUniqueName("templateObject");
+                recordTaggedTemplateString(tempVar);
                 templateArguments[0] = createLogicalOr(
                     tempVar,
                     createAssignment(