Utils: Fix TextFileFormat::readUtf8()

... with regards to line separator conversion.
This fixes two C++ unit test cases on Windows.

Change-Id: I79256a574221ec83076d984b8f353bc4c0e528a9
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/libs/utils/textfileformat.cpp

@@ -289,6 +289,8 @@ TextFileFormat::ReadResult TextFileFormat::readFileUTF8(const QString &fileName,
     if (format.codec->name() == "UTF-8" || !format.decode(data, &target)) {
         if (format.hasUtf8Bom)
             data.remove(0, 3);
+        if (format.lineTerminationMode == TextFileFormat::CRLFLineTerminator)
+            data.replace("\r\n", "\n");
         *plainText = data;
         return TextFileFormat::ReadSuccess;
     }