jsdoc template tags might be unmatched (microsoft#32936)

* jsdoc template tags might be unmatched

* Update fourslash test

Author: sandersn

src/compiler/utilities.ts

@@ -2343,7 +2343,7 @@ namespace ts {
     export function getTypeParameterFromJsDoc(node: TypeParameterDeclaration & { parent: JSDocTemplateTag }): TypeParameterDeclaration | undefined {
         const name = node.name.escapedText;
         const { typeParameters } = (node.parent.parent.parent as SignatureDeclaration | InterfaceDeclaration | ClassDeclaration);
-        return find(typeParameters!, p => p.name.escapedText === name);
+        return typeParameters && find(typeParameters, p => p.name.escapedText === name);
     }
 
     export function hasRestParameter(s: SignatureDeclaration | JSDocSignature): boolean {

tests/cases/fourslash/jsDocFunctionSignatures13.ts

@@ -0,0 +1,10 @@
+///<reference path="fourslash.ts" />
+//// /**
+////  * @template {string} K/**/ a golden opportunity
+////  */
+//// function Multimap(iv) {
+//// };
+
+
+goTo.marker('');
+verify.quickInfoIs("any");