function declareSymbol(symbolTable, parent, node, includes, excludes) {
            ts.Debug.assert(!ts.hasDynamicName(node));
            var isDefaultExport = node.flags & 512 /* Default */;
            // The exported symbol for an export default function/class node is always named "default"
            var name = isDefaultExport && parent ? "default" : getDeclarationName(node);
            var symbol;
            if (name !== undefined) {
                // Check and see if the symbol table already has a symbol with this name.  If not,
                // create a new symbol with this name and add it to the table.  Note that we don't
                // give the new symbol any flags *yet*.  This ensures that it will not conflict
                // with the 'excludes' flags we pass in.
                //
                // If we do get an existing symbol, see if it conflicts with the new symbol we're
                // creating.  For example, a 'var' symbol and a 'class' symbol will conflict within
                // the same symbol table.  If we have a conflict, report the issue on each
                // declaration we have for this symbol, and then create a new symbol for this
                // declaration.
                //
                // If we created a new symbol, either because we didn't have a symbol with this name
                // in the symbol table, or we conflicted with an existing symbol, then just add this
                // node as the sole declaration of the new symbol.
                //
                // Otherwise, we'll be merging into a compatible existing symbol (for example when
                // you have multiple 'vars' with the same name in the same container).  In this case
                // just add this node into the declarations list of the symbol.
                symbol = ts.hasProperty(symbolTable, name)
                    ? symbolTable[name]
                    : (symbolTable[name] = createSymbol(0 /* None */, name));
                if (name && (includes & 788448 /* Classifiable */)) {
                    classifiableNames[name] = name;
                }
                if (symbol.flags & excludes) {
                    if (node.name) {
                        node.name.parent = node;
                    }
                    // Report errors every position with duplicate declaration
                    // Report errors on previous encountered declarations
                    var message = symbol.flags & 2 /* BlockScopedVariable */
                        ? ts.Diagnostics.Cannot_redeclare_block_scoped_variable_0
                        : ts.Diagnostics.Duplicate_identifier_0;
                    ts.forEach(symbol.declarations, function (declaration) {
                        if (declaration.flags & 512 /* Default */) {
                            message = ts.Diagnostics.A_module_cannot_have_multiple_default_exports;
                        }
                    });
                    ts.forEach(symbol.declarations, function (declaration) {
                        file.bindDiagnostics.push(ts.createDiagnosticForNode(declaration.name || declaration, message, getDisplayName(declaration)));
                    });
                    file.bindDiagnostics.push(ts.createDiagnosticForNode(node.name || node, message, getDisplayName(node)));
                    symbol = createSymbol(0 /* None */, name);
                }
            }
            else {
                symbol = createSymbol(0 /* None */, "__missing");
            }
            addDeclarationToSymbol(symbol, node, includes);
            symbol.parent = parent;
            return symbol;
        }
Declares a Symbol for the node and adds it to symbols. Reports errors for conflicting identifier names.
@param symbolTable - The symbol table which node will be added to.
@param parent - node's parent declaration.
@param node - The declaration to be added to the symbol table
@param includes - The SymbolFlags that node has in addition to its declaration type (eg: export, ambient, etc.)
@param excludes - The flags which node cannot be declared alongside in a symbol table. Used to report forbidden declarations.