[gcc r14-8633] testsuite: fix anon6 mangling [PR112846]

[Jason Merrill]

https://gcc.gnu.org/g:209fc1e5f6c67e55e579b69f617b0b678b1bfdf0

commit r14-8633-g209fc1e5f6c67e55e579b69f617b0b678b1bfdf0
Author: Jason Merrill <jason@redhat.com>
Date:   Tue Jan 30 12:07:21 2024 -0500

    testsuite: fix anon6 mangling [PR112846]
    
    As with r14-6796-g2fa122cae50cd8, avoid mangling compatibility aliases in
    mangling tests, and test the new mangling.
    
            PR c++/112846
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/abi/anon6.C: Specify ABI v18.
            * g++.dg/abi/anon6a.C: New test for ABI v19.

Diff:
---
 gcc/testsuite/g++.dg/abi/anon6.C  |  1 +
 gcc/testsuite/g++.dg/abi/anon6a.C | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/gcc/testsuite/g++.dg/abi/anon6.C b/gcc/testsuite/g++.dg/abi/anon6.C
index 7be0b0bbdb7e..fd766109629e 100644
--- a/gcc/testsuite/g++.dg/abi/anon6.C
+++ b/gcc/testsuite/g++.dg/abi/anon6.C
@@ -1,5 +1,6 @@
 // PR c++/108566
 // { dg-do compile { target c++20 } }
+// { dg-additional-options "-fabi-version=18 -fabi-compat-version=18" }
 
 template<typename T>
 struct wrapper1 {
diff --git a/gcc/testsuite/g++.dg/abi/anon6a.C b/gcc/testsuite/g++.dg/abi/anon6a.C
new file mode 100644
index 000000000000..69c9adb42569
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/anon6a.C
@@ -0,0 +1,20 @@
+// PR c++/108566
+// { dg-do compile { target c++20 } }
+// { dg-additional-options "-fabi-compat-version=0" }
+
+template<typename T>
+struct wrapper1 {
+  union {
+    union {
+      T RightName;
+    };
+  };
+};
+
+template<auto tparam> void dummy(){}
+
+void uses() {
+  dummy<wrapper1<double>{123.0}>();
+}
+
+// { dg-final { scan-assembler "_Z5dummyITnDaXtl8wrapper1IdEtlNS1_Ut_Edi9RightNametlNS2_Ut_Edi9RightNameLd405ec00000000000EEEEEEvv" } }