Proper parenthesis for yield and await in conditional (#436)

Turns out, we need to always parenthesis when it's the first part of a conditional for both yield and await.

Fixes #433

tests/yield/__snapshots__/jsfmt.spec.js.snap

@@ -2,15 +2,41 @@ exports[`test conditional.js 1`] = `
 "function* f() {
   a = (yield) ? 1 : 1;
   a = yield 1 ? 1 : 1;
+  a = (yield 1) ? 1 : 1;
   a = 1 ? yield : yield;
   a = 1 ? yield 1 : yield 1;
 }
+
+function* f() {
+  a = yield* 1 ? 1 : 1;
+  a = (yield* 1) ? 1 : 1;
+  a = 1 ? yield* 1 : yield* 1;
+}
+
+async function f() {
+  a = await 1 ? 1 : 1;
+  a = (await 1) ? 1 : 1;
+  a = 1 ? await 1 : await 1;
+}
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 function* f() {
   a = (yield) ? 1 : 1;
   a = yield 1 ? 1 : 1;
+  a = (yield 1) ? 1 : 1;
   a = 1 ? yield : yield;
   a = 1 ? yield 1 : yield 1;
 }
+
+function* f() {
+  a = yield* 1 ? 1 : 1;
+  a = (yield* 1) ? 1 : 1;
+  a = 1 ? yield* 1 : yield* 1;
+}
+
+async function f() {
+  a = (await 1) ? 1 : 1;
+  a = (await 1) ? 1 : 1;
+  a = 1 ? await 1 : await 1;
+}
 "
 `;

tests/yield/conditional.js

@@ -1,6 +1,19 @@
 function* f() {
   a = (yield) ? 1 : 1;
   a = yield 1 ? 1 : 1;
+  a = (yield 1) ? 1 : 1;
   a = 1 ? yield : yield;
   a = 1 ? yield 1 : yield 1;
 }
+
+function* f() {
+  a = yield* 1 ? 1 : 1;
+  a = (yield* 1) ? 1 : 1;
+  a = 1 ? yield* 1 : yield* 1;
+}
+
+async function f() {
+  a = await 1 ? 1 : 1;
+  a = (await 1) ? 1 : 1;
+  a = 1 ? await 1 : await 1;
+}