Fix panic when @this tag appears inside @typedef JSDoc comment (#3921)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: jakebailey <5341706+jakebailey@users.noreply.github.com>

Author: Copilot

internal/checker/nodecopy.go

@@ -482,6 +482,9 @@ func getExistingNodeTreeVisitor(b *NodeBuilderImpl, bound *recoveryBoundary) *as
 		if node.Kind == ast.KindJSDocTypeLiteral {
 			var members []*ast.Node
 			for _, t := range node.AsJSDocTypeLiteral().JSDocPropertyTags {
+				if t.Kind != ast.KindJSDocPropertyTag && t.Kind != ast.KindJSDocParameterTag {
+					continue
+				}
 				n := t.Name()
 				var targetName *ast.Node
 				if ast.IsIdentifier(n) {

internal/parser/reparser.go

@@ -179,6 +179,9 @@ func (p *Parser) reparseJSDocTypeLiteral(t *ast.TypeNode) *ast.Node {
 		isArrayType := jstypeliteral.IsArrayType
 		properties := p.nodeSliceArena.NewSlice(0)
 		for _, prop := range jstypeliteral.JSDocPropertyTags {
+			if prop.Kind != ast.KindJSDocPropertyTag && prop.Kind != ast.KindJSDocParameterTag {
+				continue
+			}
 			jsprop := prop.AsJSDocParameterOrPropertyTag()
 			name := prop.Name()
 			if name.Kind == ast.KindQualifiedName {

testdata/baselines/reference/compiler/jsDocTypedefWithThisTag.symbols

@@ -0,0 +1,7 @@
+//// [tests/cases/compiler/jsDocTypedefWithThisTag.ts] ////
+
+=== bug.js ===
+/** @typedef T @this {object} */
+const x = 1;
+>x : Symbol(x, Decl(bug.js, 1, 5))
+

testdata/baselines/reference/compiler/jsDocTypedefWithThisTag.types

@@ -0,0 +1,8 @@
+//// [tests/cases/compiler/jsDocTypedefWithThisTag.ts] ////
+
+=== bug.js ===
+/** @typedef T @this {object} */
+const x = 1;
+>x : 1
+>1 : 1
+

testdata/tests/cases/compiler/jsDocTypedefWithThisTag.ts

@@ -0,0 +1,7 @@
+// @allowJs: true
+// @checkJs: true
+// @noEmit: true
+
+// @filename: bug.js
+/** @typedef T @this {object} */
+const x = 1;