Inlining a few small methods based on profiling dex2oat with perf.

Test: m test-art-host
Change-Id: I6313158e59592d8d132154523be9c82dda3c7eb8
diff --git a/runtime/base/mutex.h b/runtime/base/mutex.h
index c59664b..65d35ea 100644
--- a/runtime/base/mutex.h
+++ b/runtime/base/mutex.h
@@ -516,12 +516,12 @@
 // construction and releases it upon destruction.
 class SCOPED_CAPABILITY ReaderMutexLock {
  public:
-  ReaderMutexLock(Thread* self, ReaderWriterMutex& mu) ACQUIRE(mu) :
+  ReaderMutexLock(Thread* self, ReaderWriterMutex& mu) ACQUIRE(mu) ALWAYS_INLINE :
       self_(self), mu_(mu) {
     mu_.SharedLock(self_);
   }
 
-  ~ReaderMutexLock() RELEASE() {
+  ~ReaderMutexLock() RELEASE() ALWAYS_INLINE {
     mu_.SharedUnlock(self_);
   }