tst_QChar: run it also under QT_RESTRICTED_CAST_FROM_ASCII

Like QString, QChar also changes API when said macro is defined.

So, like tst_QString from 8420d3e0b205d0ef2367224afd3040c68e28bcc9
onwards, also compile tst_QChar under it, separately.

Pick-to: 6.5
Change-Id: I81d25d5bfae78b1a11d47e49aa618d079c4b09b7
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit 167b04aac89488a5f2005bd1f4dfde354f43c6a6)

tests/auto/corelib/text/qchar/CMakeLists.txt

@@ -14,10 +14,20 @@ endif()
 # Collect test data
 list(APPEND test_data "data/NormalizationTest.txt")
 
-qt_internal_add_test(tst_qchar
+foreach(test tst_qchar tst_qchar_restricted_ascii)
+    qt_internal_add_test(${test}
+        NO_BATCH
         SOURCES
            tst_qchar.cpp
         LIBRARIES
             Qt::CorePrivate
-    TESTDATA ${test_data}
+        TESTDATA
+            ${test_data}
+    )
+endforeach()
+
+qt_internal_extend_target(tst_qchar_restricted_ascii
+    DEFINES
+        QT_RESTRICTED_CAST_FROM_ASCII
+        tst_QChar=tst_QChar_restricted_ascii
 )

tests/auto/corelib/text/qchar/tst_qchar.cpp

@@ -6,6 +6,7 @@
 #include <qfile.h>
 #include <qstringlist.h>
 
+#include <climits>
 #include <type_traits>
 
 template <typename C>
@@ -33,7 +34,11 @@ static_assert(explicitly<char32_t>);
 //
 // Conversion from others
 //
+#if defined(QT_RESTRICTED_CAST_FROM_ASCII)
+static_assert(explicitly<uchar>); // via integer promotion
+#else
 static_assert(explicitly<uchar>);
+#endif
 static_assert(implicitly<short>);
 static_assert(implicitly<ushort>);
 static_assert(explicitly<int>);