fix typo

Author: zhengbli

src/compiler/binder.ts

@@ -1314,7 +1314,7 @@ namespace ts {
 
         function bindJSDocTypedefTag(node: JSDocTypedefTag) {
             forEachChild(node, n => {
-                // if the node has a fullName "A.B.C", that means symbol "C" was already bond
+                // if the node has a fullName "A.B.C", that means symbol "C" was already bound
                 // when we visit "fullName"; so when we visit the name "C" as the next child of
                 // the jsDocTypedefTag, we should skip binding it.
                 if (n === node.name && node.fullName.kind !== SyntaxKind.Identifier) {