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/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index a446701..be51232 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -19,8 +19,10 @@
 #include "utils/arm/assembler_arm.h"
 #include "utils/arm/managed_register_arm.h"
 
+#include "entrypoints/quick/quick_entrypoints.h"
 #include "mirror/array.h"
 #include "mirror/art_method.h"
+#include "thread.h"
 
 #define __ reinterpret_cast<ArmAssembler*>(GetAssembler())->