Add lexing, parsing and some semantic checking for constant buffers.

AST.jai

@@ -20,6 +20,7 @@ AST_Kind :: enum {
 	// Operator;
 	Call;
 	Struct;
+	CBuffer;
 	FieldList;
 	ArgList;
 	Variable;
@@ -39,7 +40,8 @@ AST_Node :: struct {
 
 	// @Note(niels): Children nodes can be interpreted as anything useful.
 	// for an if-statement we would have at most 2 children
-	// a property block has a child node for each field declaration etc.
+	// a property block has a field list child node which has
+	// a child node for each field declaration etc.
 	children : [..]*AST_Node;
 	parent : *AST_Node;
 
@@ -52,8 +54,6 @@ AST_Node :: struct {
 
 	token : Token;
 
-	assignment     : bool;
-
 	source_location : Source_Range;
 
 	type_variable : Type_Variable_Handle;
@@ -312,6 +312,8 @@ pretty_print_declaration :: (declaration : *AST_Node, indentation : int, builder
 	else {
 		if declaration.kind == .Struct {
 			append(builder, "struct ");
+		} else if declaration.kind == .CBuffer {
+			append(builder, "constant_buffer ");
 		}
 		print_to_builder(builder, "%", declaration.name);
 	}