[TypeChecker] NFC: Add more chained operators to make rdar://22877285 "too complex" on Linux

Author: xedin

validation-test/Sema/type_checker_perf/slow/rdar22877285.swift

@@ -3,5 +3,5 @@
 
 let j = 1
 
-_ = "a" + j + "b" + j + "c" + j
+_ = "a" + j + "b" + j + "c" + j + "d" + j
 // expected-error@-1 {{reasonable time}}