[gn build] (manually) port bba38de

Author: nico

llvm/utils/gn/secondary/compiler-rt/lib/sanitizer_common/BUILD.gn

@@ -108,6 +108,7 @@ source_set("sources") {
     "sanitizer_procmaps_linux.cpp",
     "sanitizer_procmaps_mac.cpp",
     "sanitizer_procmaps_solaris.cpp",
+    "sanitizer_ptrauth.h",
     "sanitizer_quarantine.h",
     "sanitizer_report_decorator.h",
     "sanitizer_ring_buffer.h",