Handle all overloads of String.Trim*()

Prevents mismatch between netstandard2.0 and netcoreapp2.0.

Fixes #1640

Author: ngbrown

src/NHibernate.Test/Async/Linq/FunctionTests.cs

@@ -323,6 +323,12 @@ public async Task TrimAsync()
 				Assert.AreEqual(1, await (session.Query<AnotherEntity>().CountAsync(e => e.Input.TrimStart('h') == "eh")));
 				Assert.AreEqual(1, await (session.Query<AnotherEntity>().CountAsync(e => e.Input.TrimEnd('h') == "he")));
 
+				// Check when passed as array
+				// (the single character parameter is a new overload in .netcoreapp2.0, but not net461 or .netstandard2.0).
+				Assert.AreEqual(1, await (session.Query<AnotherEntity>().CountAsync(e => e.Input.Trim(new [] { 'h' }) == "e")));
+				Assert.AreEqual(1, await (session.Query<AnotherEntity>().CountAsync(e => e.Input.TrimStart(new[] { 'h' }) == "eh")));
+				Assert.AreEqual(1, await (session.Query<AnotherEntity>().CountAsync(e => e.Input.TrimEnd(new[] { 'h' }) == "he")));
+
 				// Let it rollback to get rid of temporary changes.
 			}
 		}

src/NHibernate.Test/Linq/FunctionTests.cs

@@ -305,6 +305,12 @@ public void Trim()
 				Assert.AreEqual(1, session.Query<AnotherEntity>().Count(e => e.Input.TrimStart('h') == "eh"));
 				Assert.AreEqual(1, session.Query<AnotherEntity>().Count(e => e.Input.TrimEnd('h') == "he"));
 
+				// Check when passed as array
+				// (the single character parameter is a new overload in .netcoreapp2.0, but not net461 or .netstandard2.0).
+				Assert.AreEqual(1, session.Query<AnotherEntity>().Count(e => e.Input.Trim(new [] { 'h' }) == "e"));
+				Assert.AreEqual(1, session.Query<AnotherEntity>().Count(e => e.Input.TrimStart(new[] { 'h' }) == "eh"));
+				Assert.AreEqual(1, session.Query<AnotherEntity>().Count(e => e.Input.TrimEnd(new[] { 'h' }) == "he"));
+
 				// Let it rollback to get rid of temporary changes.
 			}
 		}

src/NHibernate/Linq/Functions/StringGenerator.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
+using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
 using NHibernate.Hql.Ast;
@@ -241,18 +242,7 @@ public class TrimGenerator : BaseHqlGeneratorForMethod
 	{
 		public TrimGenerator()
 		{
-			SupportedMethods = new HashSet<MethodInfo>
-			{
-				ReflectHelper.GetMethodDefinition<string>(s => s.Trim()),
-				ReflectHelper.GetMethodDefinition<string>(s => s.Trim('a')),
-				ReflectHelper.GetMethodDefinition<string>(s => s.Trim('a', 'a')),
-				ReflectHelper.GetMethodDefinition<string>(s => s.TrimStart()),
-				ReflectHelper.GetMethodDefinition<string>(s => s.TrimStart('a')),
-				ReflectHelper.GetMethodDefinition<string>(s => s.TrimStart('a', 'a')),
-				ReflectHelper.GetMethodDefinition<string>(s => s.TrimEnd()),
-				ReflectHelper.GetMethodDefinition<string>(s => s.TrimEnd('a')),
-				ReflectHelper.GetMethodDefinition<string>(s => s.TrimEnd('a', 'a'))
-			};
+			SupportedMethods = typeof(string).GetMethods().Where(x => new[] { "Trim", "TrimStart", "TrimEnd" }.Contains(x.Name)).ToArray();
 		}
 
 		public override HqlTreeNode BuildHql(MethodInfo method, Expression targetObject, ReadOnlyCollection<Expression> arguments, HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)