[NFC][compiler-rt][test] when using ptrauth, strip before checking if poisoned

[aralisza]

Summary

ptrauth stores info in the address of functions, so it's not the right address we should check if poisoned

rdar://75246928

[aralisza]

use ptrauth_calls

compiler-rt/test/asan/TestCases/Darwin/linked-only.cpp

 // Main executable is uninstrumented, but linked to ASan runtime.
 // Regression test for https://code.google.com/p/address-sanitizer/issues/detail?id=357.
 
 // RUN: %clangxx -g -O0 %s -c -o %t.o
 // RUN: %clangxx_asan -g -O0 %t.o -o %t
 // RUN: %run %t 2>&1 | FileCheck %s
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "sanitizer/asan_interface.h"
+#if __has_feature(ptrauth_calls)
+#  include <ptrauth.h>
+#endif
 
 void test_shadow(char *p, size_t size) {
   fprintf(stderr, "p = %p\n", p);
   char *q = (char *)__asan_region_is_poisoned(p, size);
   fprintf(stderr, "=%zd=\n", q ? q - p : -1);
 }
 
 int main(int argc, char *argv[]) {
   char *p = (char *)malloc(10000);
   test_shadow(p, 100);
   free(p);
   // CHECK: =-1=
 
-  test_shadow((char *)&main, 1);
+  char *mainptr;
+#if __has_feature(ptrauth_returns)
+  mainptr = (char *)ptrauth_strip((void *)&main, ptrauth_key_return_address);
+#else
+  mainptr = (char *)&main;
+#endif
+  test_shadow(mainptr, 1);
   // CHECK: =-1=
 
   test_shadow((char *)&p, 1);
   // CHECK: =-1=
 
   return 0;
 }