add test

Author: sakria9

clang/test/AST/ast-dump-template-argument-structural-value.cpp

@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -std=c++20 -ast-dump -ast-dump-filter=pr126341 %s | FileCheck %s
+
+template<_Complex int x>
+struct pr126341;
+template<>
+struct pr126341<{1, 2}>;
+
+// CHECK: Dumping pr126341:
+// CHECK-NEXT: ClassTemplateDecl
+// CHECK: Dumping pr126341:
+// CHECK-NEXT: ClassTemplateSpecializationDecl
+// CHECK-NEXT: `-TemplateArgument structural value '1+2i'