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/thread.cc b/runtime/thread.cc
index 0fafbfa..7470670 100644
--- a/runtime/thread.cc
+++ b/runtime/thread.cc
@@ -1400,7 +1400,8 @@
       return true;  // Ignore runtime frames (in particular callee save).
     }
     method_trace_->Set<kTransactionActive>(count_, m);
-    dex_pc_trace_->Set<kTransactionActive>(count_, m->IsProxyMethod() ? DexFile::kDexNoIndex : GetDexPc());
+    dex_pc_trace_->Set<kTransactionActive>(count_,
+        m->IsProxyMethod() ? DexFile::kDexNoIndex : GetDexPc());
     ++count_;
     return true;
   }