Specify a target cpu in test case

Hopefully, this makes the bots happy

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@284048 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 87e888e3b555baed76bb4ffe825f442b590af57e)
diff --git a/test/CodeGen/windows-swiftcall.c b/test/CodeGen/windows-swiftcall.c
index 5bd0d5f..c9d201a 100644
--- a/test/CodeGen/windows-swiftcall.c
+++ b/test/CodeGen/windows-swiftcall.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple x86_64-unknown-windows -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-unknown-windows -emit-llvm -target-cpu core2 -o - %s | FileCheck %s
 
 #define SWIFTCALL __attribute__((swiftcall))
 #define OUT __attribute__((swift_indirect_result))