Test for externality

Author: mysterymath

llvm/test/LTO/Resolution/X86/bcmp-libcall.ll

@@ -25,8 +25,8 @@ define i1 @foo(ptr %0, ptr %1, i64 %2) {
 declare i32 @memcmp(ptr, ptr, i64)
 declare i32 @bcmp_impl(ptr, ptr, i64);
 
-;; Ensure bcmp is not removed from module.
-; CHECK: define{{.*}}i32 @bcmp
+;; Ensure bcmp is not removed from module because it is external.
+; CHECK: define dso_local i32 @bcmp
 define i32 @bcmp(ptr %0, ptr %1, i64 %2) noinline {
   %r = call i32 @bcmp_impl(ptr %0, ptr %1, i64 %2)
   ret i32 %r