Allow bjects with single string literal keys in tail position

src/transforms/comprehension.lsc

@@ -109,7 +109,7 @@ transformObjectComprehensionTails(loopPath, id): void ->
         // Simple object case: { [k]: v } --> obj[k] = v
         { properties: [prop] } = expr
         t.assignmentExpression("=",
-          t.memberExpression(id, prop.key, prop.computed)~atNode(expr),
+          t.memberExpression(id, prop.key, prop.computed or (not prop.key~isa("Identifier")))~atNode(expr),
           prop.value
         )~atNode(expr)
       else:

test/fixtures/comprehensions/object-string-literal-tail/actual.js

@@ -0,0 +1 @@
+obj = {...for const x of []: {'a': 1}}

test/fixtures/comprehensions/object-string-literal-tail/expected.js

@@ -0,0 +1,3 @@
+const obj = (() => {
+  const _obj = {};for (const x of []) _obj['a'] = 1;return _obj;
+})();