Use ObjPtr for reflection.cc/h/inl

Changed Pretty helpers to use this to reduce usage of Decode. The
eventual goal is not have almost any calls to ObjPtr::Decode.

Moved ObjPtr out of mirror namespace for convenience. Added more
PoisonObjectPointers calls in class linker, thread suspension.

Bug: 31113334

Test: test-art-host

Change-Id: I44d08db5143d95ed1b65e2f00f9749ef5cf379f7
diff --git a/runtime/utils.cc b/runtime/utils.cc
index b52e2f2..0803ca7 100644
--- a/runtime/utils.cc
+++ b/runtime/utils.cc
@@ -37,6 +37,7 @@
 #include "mirror/object_array-inl.h"
 #include "mirror/string.h"
 #include "oat_quick_method_header.h"
+#include "obj_ptr-inl.h"
 #include "os.h"
 #include "scoped_thread_state_change.h"
 #include "utf-inl.h"
@@ -270,14 +271,14 @@
   }
 }
 
-std::string PrettyDescriptor(mirror::String* java_descriptor) {
+std::string PrettyStringDescriptor(ObjPtr<mirror::String> java_descriptor) {
   if (java_descriptor == nullptr) {
     return "null";
   }
   return PrettyDescriptor(java_descriptor->ToModifiedUtf8().c_str());
 }
 
-std::string PrettyDescriptor(mirror::Class* klass) {
+std::string PrettyDescriptor(ObjPtr<mirror::Class> klass) {
   if (klass == nullptr) {
     return "null";
   }
@@ -456,7 +457,7 @@
   return result;
 }
 
-std::string PrettyTypeOf(mirror::Object* obj) {
+std::string PrettyTypeOf(ObjPtr<mirror::Object> obj) {
   if (obj == nullptr) {
     return "null";
   }
@@ -471,7 +472,7 @@
   return result;
 }
 
-std::string PrettyClass(mirror::Class* c) {
+std::string PrettyClass(ObjPtr<mirror::Class> c) {
   if (c == nullptr) {
     return "null";
   }
@@ -482,7 +483,7 @@
   return result;
 }
 
-std::string PrettyClassAndClassLoader(mirror::Class* c) {
+std::string PrettyClassAndClassLoader(ObjPtr<mirror::Class> c) {
   if (c == nullptr) {
     return "null";
   }