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/monitor.h b/runtime/monitor.h
index 0b80892..15620d5 100644
--- a/runtime/monitor.h
+++ b/runtime/monitor.h
@@ -31,18 +31,16 @@
 
 namespace art {
 
+class LockWord;
 template<class T> class SirtRef;
+class Thread;
+class StackVisitor;
+typedef uint32_t MonitorId;
 
 namespace mirror {
   class ArtMethod;
   class Object;
 }  // namespace mirror
-class LockWord;
-template<class T> class SirtRef;
-class Thread;
-class StackVisitor;
-
-typedef uint32_t MonitorId;
 
 class Monitor {
  public: