Remove the value type special case from the expression builder's variable-type-replacement.

With the recent improvements, value type variables are guaranteed to already have the correct type in the ILAst, so we no longer need these hacks.

ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs

@@ -907,8 +907,6 @@ namespace ICSharpCode.Decompiler.CSharp
 			bool CanUseTypeForStackSlot(ILVariable v, IType type)
 			{
 				return v.IsSingleDefinition
-					|| IsOtherValueType(type)
-					|| v.StackType == StackType.Ref
 					|| AllStoresUseConsistentType(v.StoreInstructions, type);
 			}