Add a new bit to VarDecl to track cases where a vardecl gets an

initializer but has no "parent" PatternBindingDecl or Pattern (i.e.
paramdecls).  This is currently set on decls in the pattern of 
foreach loops and case patterns, but I'll add it to other places I
find as well.

NFC since this bit is only set and not read, just more yak shaving.


Swift SVN r23910

lib/Serialization/Serialization.cpp

@@ -1870,6 +1870,7 @@ void Serializer::writeDecl(const Decl *D) {
                           var->isObjC(),
                           var->isStatic(),
                           var->isLet(),
+                          var->hasNonPatternBindingInit(),
                           (unsigned) accessors.Kind,
                           addTypeRef(type),
                           addTypeRef(var->getInterfaceType()),