[Linker] PR33527 - Linker::LinkOnlyNeeded should import AppendingLinkage globals

Linker::LinkOnlyNeeded should always import globals with
AppendingLinkage.

This resolves PR33527.

Differential Revision: https://reviews.llvm.org/D34448

llvm-svn: 310522
diff --git a/llvm/test/Linker/Inputs/only-needed-ctors.ll b/llvm/test/Linker/Inputs/only-needed-ctors.ll
new file mode 100644
index 0000000..d95f371
--- /dev/null
+++ b/llvm/test/Linker/Inputs/only-needed-ctors.ll
@@ -0,0 +1,20 @@
+define internal void @ctor1() {
+  call void @func1()
+  ret void
+}
+
+define internal void @ctor2() {
+  ret void
+}
+
+define void @func1() {
+  ret void
+}
+
+define void @unused() {
+  ret void
+}
+
+@llvm.global_ctors = appending global[2 x{i32, void() *, i8 * }] [
+    {i32, void() *, i8 * } { i32 2, void() *@ctor1, i8 *null},
+    {i32, void() *, i8 * } { i32 7, void() *@ctor2, i8 *null}]