NH-3807 - Centeralize all use of string.Intern() and guard on use for CoreClr.

Author: ngbrown

src/NHibernate/Mapping/OneToMany.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using NHibernate.Engine;
 using NHibernate.Type;
+using NHibernate.Util;
 
 namespace NHibernate.Mapping
 {
@@ -48,7 +49,7 @@ public int ColumnSpan
 		public string ReferencedEntityName
 		{
 			get { return referencedEntityName; }
-			set { referencedEntityName = value == null ? null : string.Intern(value); }
+			set { referencedEntityName = StringHelper.InternedIfPossible(value); }
 		}
 
 		public Table ReferencingTable
@@ -161,4 +162,4 @@ public bool IsEmbedded
 			set { embedded = value; }
 		}
 	}
-}
+}

src/NHibernate/Mapping/PersistentClass.cs

@@ -71,7 +71,7 @@ public string ClassName
 			get { return className; }
 			set
 			{
-				className = value == null ? null : string.Intern(value);
+				className = StringHelper.InternedIfPossible(value);
 				mappedClass = null;
 			}
 		}
@@ -260,7 +260,7 @@ public virtual IEnumerable<Subclass> DirectSubclasses
 		public virtual string EntityName
 		{
 			get { return entityName; }
-			set { entityName = value == null ? null : String.Intern(value); }
+			set { entityName = StringHelper.InternedIfPossible(value); }
 		}
 
 		/// <summary>
@@ -520,7 +520,7 @@ public virtual IDictionary<string, string> FilterMap
 		public string LoaderName
 		{
 			get { return loaderName; }
-			set { loaderName = value == null ? null : string.Intern(value); }
+			set { loaderName = StringHelper.InternedIfPossible(value); }
 		}
 
 		public virtual ISet<string> SynchronizedTables

src/NHibernate/Util/StringHelper.cs

@@ -675,11 +675,13 @@ public static string InternedIfPossible(string str)
 				return null;
 			}
 
+#if FEATURE_STRING_INTERN
 			string interned = string.IsInterned(str);
 			if (interned != null)
 			{
 				return interned;
 			}
+#endif
 
 			return str;
 		}