As of v0.18.1 I can use `test_bitcoin-qt -platform cocoa` to run GUI tests; this opens and closes a regtest GUI a bunch of times.

As of master (6e4f6553913978fcdddba30e0bb6f97edcb12e80) it seems to ignore the `-platform cocoa` and just run the test as with `minimal`.

As seen on macOS 10.14.6. Git bisect blames a2714a5c69f0b0506689af04c3e785f71ee0915d in #16578 `Do not pass in command line arguments to QApplication` (@achow101, @ryanofsky)
#include <qt/test/apptests.h>
#include <chainparams.h>
#include <key.h>
#include <qt/bitcoin.h>
#include <qt/bitcoingui.h>
#include <qt/networkstyle.h>
#include <qt/rpcconsole.h>
#include <shutdown.h>
#include <test/setup_common.h>
#include <univalue.h>
#include <validation.h>
#if defined(HAVE_CONFIG_H)
#include <config/bitcoin-config.h>
#endif
#include <QAction>
#include <QEventLoop>
#include <QLineEdit>
#include <QScopedPointer>
#include <QTest>
#include <QTextEdit>
#include <QtGlobal>
#include <QtTest/QtTestWidgets>
#include <QtTest/QtTestGui>
namespace {
void TestRpcCommand(RPCConsole* console)