Better handling for binary operators in => bodies.

test/regression/0400/0434.unit

Index: test/regression/0400/0434.unit
diff --git a/test/regression/0400/0434.unit b/test/regression/0400/0434.unit
new file mode 100644
index 0000000000000000000000000000000000000000..408941256ba25295f670441601cc11309afb885e
--- /dev/null
+++ b/test/regression/0400/0434.unit
@@ -0,0 +1,20 @@
+>>> (indent 2)
+  @eventHandler
+  bool computeChangePasswordDisabled(
+          String email, String password, String newPassword) =>
+      email == null ||
+          email.isEmpty ||
+          password == null ||
+          password.isEmpty ||
+          newPassword == null ||
+          newPassword.isEmpty;
+<<<
+  @eventHandler
+  bool computeChangePasswordDisabled(
+          String email, String password, String newPassword) =>
+      email == null ||
+      email.isEmpty ||
+      password == null ||
+      password.isEmpty ||
+      newPassword == null ||
+      newPassword.isEmpty;