8373207: Make DeferredStatic class template constant initializable

Reviewed-by: jsjolen, stefank, iwalulya

Author: Kim Barrett

src/hotspot/share/utilities/deferredStatic.hpp

@@ -35,7 +35,7 @@
 // object must be explicitly initialized before use. This avoids problems
 // resulting from the unspecified initialization time and ordering between
 // different objects that comes from using undeferred objects (the so-called
-// "Static Initialization Order Fiasco).
+// "Static Initialization Order Fiasco").
 //
 // Once initialized, the object is never destroyed. This avoids similar issues
 // with the timing and ordering of destruction on normal program exit.
@@ -53,7 +53,7 @@ class DeferredStatic {
 public:
   NONCOPYABLE(DeferredStatic);
 
-  DeferredStatic()
+  constexpr DeferredStatic()
   DEBUG_ONLY(: _initialized(false)) {
     // Do not construct value, on purpose.
   }