src/vs/platform/terminal/node/windowsShellHelper.ts/WindowsShellHelper/getShellType
class WindowsShellHelper:	getShellType(executable: string): TerminalShellType {
		switch (executable.toLowerCase()) {
			case 'cmd.exe':
				return WindowsShellType.CommandPrompt;
			case 'powershell.exe':
			case 'pwsh.exe':
				return WindowsShellType.PowerShell;
			case 'bash.exe':
			case 'git-cmd.exe':
				return WindowsShellType.GitBash;
			case 'wsl.exe':
			case 'ubuntu.exe':
			case 'ubuntu1804.exe':
			case 'kali.exe':
			case 'debian.exe':
			case 'opensuse-42.exe':
			case 'sles-12.exe':
				return WindowsShellType.Wsl;
			default:
				return undefined;
		}
	}