Index: test/COFF/Inputs/mangled-qux.ll
===================================================================
--- /dev/null
+++ test/COFF/Inputs/mangled-qux.ll
@@ -0,0 +1,28 @@
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.0.24215"
+
+%class.baz = type { %class.bar }
+%class.bar = type { i32 (...)** }
+
+$"\01?x@bar@@UEBA_NXZ" = comdat any
+
+$"\01??_7baz@@6B@" = comdat any
+
+$"\01??_Gbaz@@UEAAPEAXI@Z" = comdat any
+
+@"\01??_7baz@@6B@" = linkonce_odr unnamed_addr constant { [2 x i8*] } { [2 x i8*] [i8* bitcast (i8* (%class.baz*, i32)* @"\01??_Gbaz@@UEAAPEAXI@Z" to i8*), i8* bitcast (i1 (%class.bar*)* @"\01?x@bar@@UEBA_NXZ" to i8*)] }, comdat, !type !0, !type !1
+
+define void @"\01?qux@@YAXXZ"() local_unnamed_addr {
+  ret void
+}
+
+define linkonce_odr i8* @"\01??_Gbaz@@UEAAPEAXI@Z"(%class.baz* %this, i32 %should_call_delete) unnamed_addr comdat {
+  ret i8* null
+}
+
+define linkonce_odr zeroext i1 @"\01?x@bar@@UEBA_NXZ"(%class.bar* %this) unnamed_addr comdat {
+  ret i1 false
+}
+
+!0 = !{i64 0, !"?AVbar@@"}
+!1 = !{i64 0, !"?AVbaz@@"}
Index: test/COFF/thinlto-mangled.ll
===================================================================
--- /dev/null
+++ test/COFF/thinlto-mangled.ll
@@ -0,0 +1,16 @@
+; RUN: opt -thinlto-bc %s -o %t.obj
+; RUN: opt -thinlto-bc %S/Inputs/mangled-qux.ll -o %T/mangled-qux.obj
+; RUN: lld-link -out:%t.exe -entry:main %t.obj %T/mangled-qux.obj
+
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.0.24215"
+
+%"class.bar" = type { i32 (...)**, i8*, i8*, i8*, i32 }
+
+define i32 @main() {
+  ret i32 0
+}
+
+define available_externally zeroext i1 @"\01?x@bar@@UEBA_NXZ"(%"class.bar"* %this) unnamed_addr align 2 {
+  ret i1 false
+}