Index: lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
===================================================================
--- lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
+++ lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
@@ -973,8 +973,10 @@
     break;
 
   case DW_ATE_lo_user:
-    // This has been seen to mean DW_AT_complex_integer
-    if (type_name.contains("complex")) {
+    // Clang and GCC use this for DW_AT_complex_integer. GCC is emitting for
+    // base types other than int the name '__unknown__' with the correct bit
+    // size, so we also treat that as a complex integer type.
+    if (type_name.contains("complex") || type_name == "__unknown__") {
       CompilerType complex_int_clang_type =
           GetBuiltinTypeForDWARFEncodingAndBitSize("int", DW_ATE_signed,
                                                    bit_size / 2);