Force inlining on trivial accessors.

Make volatility for GetFieldObject a template parameter.
Move some trivial mirror::String routines to a -inl.h.

Bug: 14285442

Change-Id: Ie23b11d4f18cb15a62c3bbb42837a8aaf6b68f92
diff --git a/runtime/mirror/stack_trace_element.cc b/runtime/mirror/stack_trace_element.cc
index 5217e5e..f220039 100644
--- a/runtime/mirror/stack_trace_element.cc
+++ b/runtime/mirror/stack_trace_element.cc
@@ -60,13 +60,13 @@
 void StackTraceElement::Init(SirtRef<String>& declaring_class, SirtRef<String>& method_name,
                              SirtRef<String>& file_name, int32_t line_number) {
   SetFieldObject<kTransactionActive>(OFFSET_OF_OBJECT_MEMBER(StackTraceElement, declaring_class_),
-                                     declaring_class.get(), false);
+                                     declaring_class.get());
   SetFieldObject<kTransactionActive>(OFFSET_OF_OBJECT_MEMBER(StackTraceElement, method_name_),
-                                     method_name.get(), false);
+                                     method_name.get());
   SetFieldObject<kTransactionActive>(OFFSET_OF_OBJECT_MEMBER(StackTraceElement, file_name_),
-                                     file_name.get(), false);
+                                     file_name.get());
   SetField32<kTransactionActive>(OFFSET_OF_OBJECT_MEMBER(StackTraceElement, line_number_),
-                                 line_number, false);
+                                 line_number);
 }
 
 void StackTraceElement::VisitRoots(RootCallback* callback, void* arg) {