Add a typecheck perf test for inferring array-of-tuples.

Author: rudkx

validation-test/Sema/type_checker_perf_failing/array_of_tuples.swift.gyb

@@ -0,0 +1,9 @@
+// RUN: not %scale-test -O --begin 1 --end 3 --step 1 --select incrementScopeCounter %s
+// REQUIRES: OS=macosx
+// REQUIRES: asserts
+
+let a = [
+%for i in range(0, N):
+  (1, 1),
+%end
+]