src/goGenerateTests: fix method can not generate test in gopls document symbol

Gopls's document symbol provider classifies methods correctly, while `go-outline`-based document symbol provider marks them as "function". The difference caused regression after change for #1020.

Fixes #2091

Change-Id: I1b92753132be26b528f994ae42af32c723dd7ce2
GitHub-Last-Rev: 6483108
GitHub-Pull-Request: #2090
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/389994
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Trust: Suzy Mueller <suzmue@golang.org>

Author: Pavle Lee

src/goGenerateTests.ts

@@ -227,5 +227,5 @@ function generateTests(conf: Config, goConfig: vscode.WorkspaceConfiguration): P
 async function getFunctions(doc: vscode.TextDocument): Promise<vscode.DocumentSymbol[]> {
 	const documentSymbolProvider = new GoDocumentSymbolProvider();
 	const symbols = await documentSymbolProvider.provideDocumentSymbols(doc, null);
-	return symbols[0].children.filter((sym) => sym.kind === vscode.SymbolKind.Function);
+	return symbols[0].children.filter((sym) => [vscode.SymbolKind.Function, vscode.SymbolKind.Method].includes(sym.kind));
 }