[X86] Add mtune command line test cases that should have gone with 4cbceb74bb5676d0181d4d0cab5194d90a42c2ec
diff --git a/clang/test/CodeGen/tune-cpu.c b/clang/test/CodeGen/tune-cpu.c
new file mode 100644
index 0000000..60c2c30
--- /dev/null
+++ b/clang/test/CodeGen/tune-cpu.c
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -triple i686-linux-gnu -target-cpu i686 -tune-cpu nehalem -emit-llvm %s -o - | FileCheck %s
+
+int baz(int a) { return 4; }
+
+// CHECK: baz{{.*}} #0
+// CHECK: #0 = {{.*}}"target-cpu"="i686" "target-features"="+cx8,+x87" "tune-cpu"="nehalem"