[PAC] Add support for __ptrauth type qualifier (#100830)

The qualifier allows programmer to directly control how pointers are
signed when they are stored in a particular variable.

The qualifier takes three arguments: the signing key, a flag specifying
whether address discrimination should be used, and a non-negative
integer that is used for additional discrimination.

```
typedef void (*my_callback)(const void*);
my_callback __ptrauth(ptrauth_key_process_dependent_code, 1, 0xe27a) callback;
```

Co-Authored-By: John McCall rjmccall@apple.com

1 files changed, 3 insertions, 0 deletions

diff --git a/libcxxabi/test/test_demangle.pass.cpp b/libcxxabi/test/test_demangle.pass.cpp
index abaa787f5432..53da1bf6765e 100644
--- a/libcxxabi/test/test_demangle.pass.cpp
+++ b/libcxxabi/test/test_demangle.pass.cpp
@@ -30243,6 +30243,9 @@ const char* cases[][2] = {
     {"_Z1fDSDRm", "f(_Sat unsigned long _Fract)"},
 
     {"_Z11bfloat16addDF16bDF16b", "bfloat16add(std::bfloat16_t, std::bfloat16_t)"},
+
+    {"_Z3fooPU9__ptrauthILj3ELb1ELj234EEPi", "foo(int* __ptrauth<3u, true, 234u>*)"},
+    {"_Z3fooIPU9__ptrauthILj1ELb0ELj64EEPiEvT_", "void foo<int* __ptrauth<1u, false, 64u>*>(int* __ptrauth<1u, false, 64u>*)"},
     // clang-format on
 };