Include PSTATE in tombstones on arm64.

A thread's PSTATE can sometimes be critical for understanding a crash,
especially with MTE and other new features that store per-thread state
in PSTATE.

Bug: 135772972
Change-Id: I1bee25bffe7eea395f04b6449dc9227298cf866e
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index d246722..e0f8aeb 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -391,7 +391,7 @@
   std::vector<std::pair<std::string, uint64_t>> special_row;
 
 #if defined(__arm__) || defined(__aarch64__)
-  static constexpr const char* special_registers[] = {"ip", "lr", "sp", "pc"};
+  static constexpr const char* special_registers[] = {"ip", "lr", "sp", "pc", "pst"};
 #elif defined(__i386__)
   static constexpr const char* special_registers[] = {"ebp", "esp", "eip"};
 #elif defined(__x86_64__)