Saturated Arithmetic (#54)

Add missing description for saturated arithmetic mode on the MSVC toolset

ltx/exprs.tex

@@ -2184,6 +2184,7 @@ \subsection{Dyadic operators}
 	\enumerator{MsvcBuiltinIsPointerInterconvertibleWithClass}
 	\enumerator{MsvcBuiltinIsCorrespondingMember}
 	\enumerator{MsvcIntrinsic}
+	\enumerator{MsvcSaturatedArithmetic}
 \end{Enumeration}
 
 \ifcSortSection{Unknown}{DyadicOperator} 
@@ -2485,6 +2486,11 @@ \subsection{Dyadic operators}
 The first operand is an integer constant describing the intrinsic; the second operand is the argument list.
 See also \sortref{Call}{ExprSort}.
 
+\ifcSortSection{MsvcSaturatedArithmetic}{DyadicOpererator}
+An MSVC intrinsic for an abstract machine saturated arithemtic operation. 
+If the arithmetic computation described by the first operand overflows, 
+then the result is the saturated value indicated by the second operand.
+
 
 \subsection{Triadic operators}
 \label{sec:ifc:OperatorSort:Triadic}