Add an LTO test that uses 'ar' to create a static library (#41242)

Author: kubamracek

test/Interpreter/lto_static_lib.swift

@@ -0,0 +1,17 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift -parse-as-library -lto=llvm-thin %s -emit-bc -o %t/a.o %lto_flags
+// RUN: ar -r -s %t/archive.a %t/a.o
+// RUN: %target-clang %t/archive.a -isysroot %sdk -L%swift_obj_root/lib/swift/%target-sdk-name -flto -o %t/main
+// RUN: %target-run %t/main | %FileCheck %s
+
+// REQUIRES: executable_test
+// REQUIRES: OS=macosx
+// REQUIRES: no_asan
+
+@_cdecl("main")
+func main() -> Int {
+	print("Hello!")
+	return 0
+}
+
+// CHECK: Hello!