More allocation code optimizations.

- Inline Class::AllocObject() and Array::Alloc().
- Inline some short Mutex functions and add LIKELY/UNLIKELY to some
  Mutex functions.
- This change improves the Ritz MemAllocTest by ~6% on Nexus 4 and
  ~10% on host.

Bug: 9986565
Change-Id: I1606c74ddb21676cbc1de1a40e9b076fc23eaea4
diff --git a/runtime/mirror/string.cc b/runtime/mirror/string.cc
index f8a0e53..7d968c7 100644
--- a/runtime/mirror/string.cc
+++ b/runtime/mirror/string.cc
@@ -17,6 +17,7 @@
 #include "string.h"
 
 #include "array.h"
+#include "class-inl.h"
 #include "gc/accounting/card_table-inl.h"
 #include "intern_table.h"
 #include "object-inl.h"
@@ -285,4 +286,3 @@
 
 }  // namespace mirror
 }  // namespace art
-