IRgen support for weak_import.
 - <rdar://problem/6652110> clang should support weak_import


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66270 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/attributes.c b/test/CodeGen/attributes.c
index 171c810..25b9fd0 100644
--- a/test/CodeGen/attributes.c
+++ b/test/CodeGen/attributes.c
@@ -13,6 +13,8 @@
 // RUN: grep '@t12 =.*section "SECT"' %t &&
 // RUN: grep '@t13 =.*section "SECT"' %t &&
 // RUN: grep '@t14.x =.*section "SECT"' %t
+// RUN: grep 'declare extern_weak i32 @t15()' %t &&
+// RUN: grep '@t16 = extern_weak global i32' %t
 
 void t1() __attribute__((noreturn));
 void t1() {}
@@ -47,3 +49,11 @@
 void t14(void) {
   static int x __attribute__((section("SECT"))) = 0;
 }
+
+int __attribute__((weak_import)) t15(void);
+extern int t16 __attribute__((weak_import));
+int t17() {
+  return t15() + t16;
+}
+
+