Fix exception when decompiling a try-catch block without finally block.

ICSharpCode.Decompiler/Ast/AstMetodBodyBuilder.cs

@@ -157,9 +157,9 @@ namespace Decompiler
 					FalseStatement = TransformBlock(conditionalNode.TrueBlock)
 				};
 			} else if (node is ILTryCatchBlock) {
-				ILTryCatchBlock tryCachNode = ((ILTryCatchBlock)node);
+				ILTryCatchBlock tryCatchNode = ((ILTryCatchBlock)node);
 				List<Ast.CatchClause> catchClauses = new List<CatchClause>();
-				foreach (var catchClause in tryCachNode.CatchBlocks) {
+				foreach (var catchClause in tryCatchNode.CatchBlocks) {
 					catchClauses.Add(new Ast.CatchClause {
 						Type = AstBuilder.ConvertType(catchClause.ExceptionType),
 						VariableName = "exception",
@@ -167,9 +167,9 @@ namespace Decompiler
 					});
 				}
 				yield return new Ast.TryCatchStatement {
-					TryBlock = TransformBlock(tryCachNode.TryBlock),
+					TryBlock = TransformBlock(tryCatchNode.TryBlock),
 					CatchClauses = catchClauses,
-					FinallyBlock = TransformBlock(tryCachNode.FinallyBlock)
+					FinallyBlock = tryCatchNode.FinallyBlock != null ? TransformBlock(tryCatchNode.FinallyBlock) : null
 				};
 			} else if (node is ILBlock) {
 				yield return TransformBlock((ILBlock)node);

ICSharpCode.Decompiler/ILAst/ILAstOptimizer.cs

@@ -52,6 +52,7 @@ namespace Decompiler.ControlFlow
 				foreach(ILTryCatchBlock.CatchBlock catchBlock in tryCatchBlock.CatchBlocks) {
 					Optimize(ref catchBlock.Body);
 				}
+				if (tryCatchBlock.FinallyBlock != null)
 					Optimize(ref tryCatchBlock.FinallyBlock.Body);
 			}
 			

ICSharpCode.Decompiler/ILAst/ILAstTypes.cs

@@ -93,6 +93,7 @@ namespace Decompiler
 			foreach (var catchBlock in this.CatchBlocks) {
 				yield return catchBlock;
 			}
+			if (this.FinallyBlock != null)
 				yield return this.FinallyBlock;
 		}