Better handling for binary operators in => bodies.

test/splitting/mixed.stmt

Index: test/splitting/mixed.stmt
diff --git a/test/splitting/mixed.stmt b/test/splitting/mixed.stmt
index 5e641cbedebc5dc96979e1fd2135526204480129..33cdba44bf5f5023add63a19a9ba8f422f48079c 100644
--- a/test/splitting/mixed.stmt
+++ b/test/splitting/mixed.stmt
@@ -95,14 +95,15 @@ function(
 receiver.firstMethod().next((parameter) => longIdentifier == veryLongIdentifier);
 <<<
 receiver.firstMethod().next(
-    (parameter) => longIdentifier ==
+    (parameter) =>
+        longIdentifier ==
         veryLongIdentifier);
 >>> wrap after =>
 receiver.firstMethod().next(() => veryveryveryverylongIdentifier == veryLongIdentifier);
 <<<
 receiver.firstMethod().next(() =>
     veryveryveryverylongIdentifier ==
-        veryLongIdentifier);
+    veryLongIdentifier);
 >>> wrap at nested binary operator
 receiver.firstMethod().next(longIdentifier == veryLongIdentifier);
 <<<
@@ -197,4 +198,16 @@ longIdentifier +
 <<<
 longIdentifier +
         (longIdentifier ? 0 : 1) ==
-    identifier;
+    identifier;
+>>> normal indent before unsplit binary operators in => body
+veryLongFunction() => extremelyLongArgument + argument;
+<<<
+veryLongFunction() =>
+    extremelyLongArgument + argument;
+>>> no extra indent before binary operators in => body
+veryLongFunction() => longArgument + longArgument + longArgument;
+<<<
+veryLongFunction() =>
+    longArgument +
+    longArgument +
+    longArgument;