Add missing disposals (microsoft#155976)

* Add missing disposals

I did some V8 heap profiling and found a few more places where
references to closed terminals prevents them from being garbage
collected.

* Let closed terminals be garbage collected

Action bars are not disposed when a terminal is closed, they are cached
in the list until you open a new terminal, so manually clear it to make
it possible to garbage collect the closed terminal directly.

Author: SvanT

src/vs/workbench/contrib/terminal/browser/terminalInstance.ts

@@ -537,7 +537,7 @@ export class TerminalInstance extends Disposable implements ITerminalInstance {
 				this._labelComputer?.refreshLabel();
 			}
 		}));
-		this._workspaceContextService.onDidChangeWorkspaceFolders(() => this._labelComputer?.refreshLabel());
+		this.addDisposable(this._workspaceContextService.onDidChangeWorkspaceFolders(() => this._labelComputer?.refreshLabel()));
 
 		// Clear out initial data events after 10 seconds, hopefully extension hosts are up and
 		// running at that point.
@@ -760,11 +760,11 @@ export class TerminalInstance extends Disposable implements ITerminalInstance {
 
 		this._loadTypeAheadAddon(xterm);
 
-		this._configurationService.onDidChangeConfiguration(e => {
+		this.addDisposable(this._configurationService.onDidChangeConfiguration(e => {
 			if (e.affectsConfiguration(TerminalSettingId.LocalEchoEnabled)) {
 				this._loadTypeAheadAddon(xterm);
 			}
-		});
+		}));
 
 		this._pathService.userHome().then(userHome => {
 			this._userHome = userHome.fsPath;

src/vs/workbench/contrib/terminal/browser/terminalTabsList.ts

@@ -458,12 +458,14 @@ class TerminalTabsRenderer implements IListRenderer<ITerminalInstance, ITerminal
 	disposeElement(instance: ITerminalInstance, index: number, templateData: ITerminalTabEntryTemplate): void {
 		templateData.elementDisposables?.dispose();
 		templateData.elementDisposables = undefined;
+		templateData.actionBar.clear();
 	}
 
 	disposeTemplate(templateData: ITerminalTabEntryTemplate): void {
 		templateData.elementDisposables?.dispose();
 		templateData.elementDisposables = undefined;
 		templateData.label.dispose();
+		templateData.actionBar.clear();
 	}
 
 	fillActionBar(instance: ITerminalInstance, template: ITerminalTabEntryTemplate): void {

src/vs/workbench/contrib/terminal/browser/xterm/decorationAddon.ts

@@ -76,7 +76,7 @@ export class DecorationAddon extends Disposable implements ITerminalAddon {
 		this._register(this._contextMenuService.onDidHideContextMenu(() => this._contextMenuVisible = false));
 		this._hoverDelayer = this._register(new Delayer(this._configurationService.getValue('workbench.hover.delay')));
 
-		this._configurationService.onDidChangeConfiguration(e => {
+		this._register(this._configurationService.onDidChangeConfiguration(e => {
 			if (e.affectsConfiguration(TerminalSettingId.ShellIntegrationDecorationIcon) ||
 				e.affectsConfiguration(TerminalSettingId.ShellIntegrationDecorationIconSuccess) ||
 				e.affectsConfiguration(TerminalSettingId.ShellIntegrationDecorationIconError)) {
@@ -92,8 +92,8 @@ export class DecorationAddon extends Disposable implements ITerminalAddon {
 				}
 				this._updateDecorationVisibility();
 			}
-		});
-		this._themeService.onDidColorThemeChange(() => this._refreshStyles(true));
+		}));
+		this._register(this._themeService.onDidColorThemeChange(() => this._refreshStyles(true)));
 		this._updateDecorationVisibility();
 		this._register(this._capabilities.onDidAddCapability(c => {
 			if (c === TerminalCapability.CommandDetection) {