Add resource chapter documenting buffers and bindings

This adds a resource chapter that documents typed and raw buffers including their methods and compatible operators along with short descriptions of their functionality. It also adds a description of binding annotations for all types. Stub sections are included for constant buffers and samplers, but no information is provided as yet.

Fixes llvm/wg-hlsl#55
Fixes llvm/wg-hlsl#56

specs/language/expressions.tex

@@ -161,8 +161,10 @@
 
 \p A \textit{postfix-expression} followed by an expression in square brackets
 (\texttt{[ ]}) is a subscript expression. In an array subscript expression of
-the form \texttt{E1[E2]}, \texttt{E1} must either be a variable of array of
-\texttt{T[]}, or an object of type \texttt{T} where \texttt{T} provides an
+the form \texttt{E1[E2]}, \texttt{E1} must either be a variable of array,
+vector, matrix, typed buffer (\ref{Resources.tybuf}), or structured buffer
+(\ref{Resources.stbufs}), with elements of type \texttt{T[]} or an
+object of type \texttt{T} where \texttt{T} provides an
 overloaded implementation of \texttt{operator[]} (\ref{Overload}).\footnote{HLSL
 does not support the base address of a subscript operator being the expression
 inside the braces, which is valid in C and C++.}

specs/language/hlsl.tex

@@ -91,6 +91,7 @@
 \input{statements}
 \input{declarations}
 \input{overloading}
+\input{resources}
 
 \input{placeholders} % Declare placeholder references