Keep copy propagation enabled

ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs

@@ -60,7 +60,7 @@ namespace ICSharpCode.Decompiler.CSharp
 				new ConditionDetection(),
 				new ILInlining(),
 				new TransformInlineAssignment(),
-//				new CopyPropagation(),
+				new CopyPropagation(),
 				new InlineCompilerGeneratedVariables(),
 				new ExpressionTransforms(), // must run once before "the loop" to allow RemoveDeadVariablesInit
 				new RemoveDeadVariableInit(), // must run after ExpressionTransforms because it does not handle stobj(ldloca V, ...)

ICSharpCode.Decompiler/IL/Transforms/CopyPropagation.cs

@@ -78,6 +78,8 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				case OpCode.LdsFlda:
 					// All address-loading instructions always return the same value for a given operand/argument combination,
 					// so they can be safely copied.
+					// ... except for LdElema and LdFlda, because those might throw an exception, and we don't want to
+					// change the place where the exception is thrown.
 					return true;
 				case OpCode.LdLoc:
 					var v = ((LdLoc)value).Variable;