Remove flags from `box` that indicate memory access and ability to throw

ICSharpCode.Decompiler/IL/Instructions.cs

@@ -318,7 +318,6 @@ namespace ICSharpCode.Decompiler.IL
 			set {
 				ValidateChild(value);
 				SetChildInstruction(ref this.argument, value, 0);
-				InvalidateFlags();
 			}
 		}
 		protected sealed override int GetChildCount()
@@ -4356,24 +4355,6 @@ namespace ICSharpCode.Decompiler.IL
 			set { type = value; InvalidateFlags(); }
 		}
 		public override StackType ResultType { get { return StackType.O; } }
-		protected override InstructionFlags ComputeFlags()
-		{
-			var baseFlags = base.ComputeFlags();
-			if (baseFlags == InstructionFlags.None && Type.Equals(Argument.InferType(null)))
-			{
-				return InstructionFlags.None;
-			}
-			return baseFlags | InstructionFlags.SideEffect | InstructionFlags.MayThrow;
-		}
-		public override InstructionFlags DirectFlags {
-			get {
-				if (Flags == InstructionFlags.None)
-				{
-					return InstructionFlags.None;
-				}
-				return base.DirectFlags | InstructionFlags.SideEffect | InstructionFlags.MayThrow;
-			}
-		}
 		public override void WriteTo(ITextOutput output, ILAstWritingOptions options)
 		{
 			WriteILRange(output, options);

ICSharpCode.Decompiler/IL/Instructions.tt

@@ -266,7 +266,7 @@
 			CustomInvariant("CheckTargetSlot();")),
 
 		new OpCode("box", "Boxes a value.",
-			Unary, HasTypeOperand, MemoryAccess, MayThrow, ResultType("O")),
+			Unary, HasTypeOperand, ResultType("O")),
 		new OpCode("unbox", "Compute address inside box.",
 			Unary, HasTypeOperand, MayThrow, ResultType("Ref")),
 		new OpCode("unbox.any", "Unbox a value.",