Fix build with no-cast-from-ascii

Change-Id: I720ceb4e511c914b924c473470f65b5b248f682a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/tools/qfloat16-tables/gen_qfloat16_tables.cpp

@@ -68,7 +68,7 @@ qint32 main(qint32 argc, char **argv)
         return -1;
     }
 
-    QFile fid(argv[1]);
+    QFile fid(QFile::decodeName(argv[1]));
     if (!fid.open(QIODevice::WriteOnly | QIODevice::Text)) {
         qWarning() << "Abort: Failed to open/create file" << fid.fileName();
         return -1;

src/tools/tracegen/helpers.cpp

@@ -46,7 +46,7 @@ QString includeGuard(const QString &filename)
 
     for (int i = 0; i < guard.size(); ++i) {
         if (!guard.at(i).isLetterOrNumber())
-            guard[i] = QChar('_');
+            guard[i] = QLatin1Char('_');
     }
 
     return guard;