[LTO] Add test to ensure objc-arc-contract is executed.

This test adds additional test coverage for upcoming refactorings.

llvm/test/LTO/X86/objc-arc-contract.ll

@@ -0,0 +1,13 @@
+; RUN: llvm-as < %s >%t.bc
+; RUN: llvm-lto -debug-pass=Arguments -exported-symbol=_f -o /dev/null %t.bc 2>&1 -disable-verify | FileCheck %s
+
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.10.0"
+
+; Make sure -objc-arc-contract is executed.
+; CHECK: Pass Arguments: {{.*}} -objc-arc-contract
+
+define void @f() {
+entry:
+  ret void
+}