Do not require mutator lock for some `ArtField` fields.

Namely for `access_flags_` and `offset_`. The `ArtField` has
not been a managed heap object for a very long time, so we
do not need to guard these primitive fields with the mutator
lock. And we similarly do not require the mutator lock for
`ArtMethod::access_flags_` either.

Test: Rely on TreeHugger.
Change-Id: I6522dad83089a742131e6e8689db04a19bd30ead
diff --git a/runtime/art_field.h b/runtime/art_field.h
index c8d8e8c..4e77e7f 100644
--- a/runtime/art_field.h
+++ b/runtime/art_field.h
@@ -55,24 +55,24 @@
     return access_flags_;
   }
 
-  void SetAccessFlags(uint32_t new_access_flags) REQUIRES_SHARED(Locks::mutator_lock_) {
+  void SetAccessFlags(uint32_t new_access_flags) {
     // Not called within a transaction.
     access_flags_ = new_access_flags;
   }
 
-  bool IsPublic() REQUIRES_SHARED(Locks::mutator_lock_) {
+  bool IsPublic() {
     return (GetAccessFlags() & kAccPublic) != 0;
   }
 
-  bool IsStatic() REQUIRES_SHARED(Locks::mutator_lock_) {
+  bool IsStatic() {
     return (GetAccessFlags() & kAccStatic) != 0;
   }
 
-  bool IsFinal() REQUIRES_SHARED(Locks::mutator_lock_) {
+  bool IsFinal() {
     return (GetAccessFlags() & kAccFinal) != 0;
   }
 
-  bool IsPrivate() REQUIRES_SHARED(Locks::mutator_lock_) {
+  bool IsPrivate() {
     return (GetAccessFlags() & kAccPrivate) != 0;
   }
 
@@ -86,7 +86,7 @@
   }
 
   // Offset to field within an Object.
-  MemberOffset GetOffset() REQUIRES_SHARED(Locks::mutator_lock_) {
+  MemberOffset GetOffset() {
     return MemberOffset(offset_);
   }
 
@@ -179,7 +179,7 @@
     visitor.VisitRoot(declaring_class_.AddressWithoutBarrier());
   }
 
-  bool IsVolatile() REQUIRES_SHARED(Locks::mutator_lock_) {
+  bool IsVolatile() {
     return (GetAccessFlags() & kAccVolatile) != 0;
   }