tst_qtextcodec: Use qt_test_helper functionality

The helper application is only needed for Unix platforms, so there is no
need to build it for other configurations.

Change-Id: I4ebb896c66d3ded016f72fdbe631ec2f1276db22
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>

tests/auto/corelib/codecs/qtextcodec/echo/echo.pro

@@ -1,6 +1,4 @@
 SOURCES += main.cpp
 QT = core
-CONFIG -= app_bundle debug_and_release_target
-CONFIG += console
-
 
+load(qt_test_helper)

tests/auto/corelib/codecs/qtextcodec/qtextcodec.pro

@@ -1,2 +1,3 @@
 TEMPLATE = subdirs
-SUBDIRS = test echo
+SUBDIRS = test.pro
+unix: SUBDIRS += echo

tests/auto/corelib/codecs/qtextcodec/test.pro

@@ -0,0 +1,6 @@
+CONFIG += testcase
+QT = core testlib
+SOURCES = tst_qtextcodec.cpp
+
+TARGET = tst_qtextcodec
+TESTDATA += *.txt

tests/auto/corelib/codecs/qtextcodec/test/test.pro

@@ -1,13 +0,0 @@
-CONFIG += testcase
-QT = core testlib
-SOURCES = ../tst_qtextcodec.cpp
-
-TARGET = ../tst_qtextcodec
-win32 {
-    CONFIG(debug, debug|release) {
-        TARGET = ../../debug/tst_qtextcodec
-    } else {
-        TARGET = ../../release/tst_qtextcodec
-    }
-}
-TESTDATA += ../*.txt

tests/auto/corelib/codecs/qtextcodec/tst_qtextcodec.cpp

@@ -2092,7 +2092,7 @@ void tst_QTextCodec::toLocal8Bit()
     QSKIP("No qprocess support", SkipAll);
 #else
     QProcess process;
-    process.start("echo/echo");
+    process.start("echo_helper");
     QString string(QChar(0x410));
     process.write((const char*)string.utf16(), string.length()*2);