Make the C++11 atomic support the default, if available

Change-Id: Ib056b47dde3341ef9a52ffff13ef1647ccd607b1
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

src/corelib/thread/qbasicatomic.h

@@ -39,11 +39,13 @@
 #if defined(QT_BOOTSTRAPPED)
 #  include <QtCore/qatomic_bootstrap.h>
 
-// The following two are used for testing only.
-// Note that we don't check the compiler support -- you had better
-// know what you're doing if you set them
-#elif defined(QT_ATOMIC_FORCE_CXX11)
+// If C++11 atomics are supported, use them!
+#elif defined(Q_COMPILER_ATOMICS) && defined(Q_COMPILER_CONSTEXPR) && !defined(QT_ATOMIC_FORCE_NO_CXX11)
 #  include <QtCore/qatomic_cxx11.h>
+
+// The following is used for testing only.
+// Note that we don't check the compiler support -- you had better
+// know what you're doing if you set it
 #elif defined(QT_ATOMIC_FORCE_GCC)
 #  include <QtCore/qatomic_gcc.h>
 
@@ -66,8 +68,6 @@
 #  include <QtCore/qatomic_x86.h>
 
 // Fallback compiler dependent implementation
-#elif defined(Q_COMPILER_ATOMICS) && defined(Q_COMPILER_CONSTEXPR)
-#  include <QtCore/qatomic_cxx11.h>
 #elif defined(Q_CC_GNU)
 #  include <QtCore/qatomic_gcc.h>
 

tests/auto/corelib/thread/qatomicinteger/qatomicinteger.pri

@@ -3,9 +3,9 @@ TYPE = $$basename(_PRO_FILE_PWD_)
 dn = $$dirname(_PRO_FILE_PWD_)
 FORCE = $$basename(dn)
 
-equals(FORCE, cxx11) {
-    suffix = Cxx11_$$TYPE
-    DEFINES += QT_ATOMIC_FORCE_CXX11
+equals(FORCE, no-cxx11) {
+    suffix = NoCxx11_$$TYPE
+    DEFINES += QT_ATOMIC_FORCE_NO_CXX11
 } else: equals(FORCE, gcc) {
     suffix = Gcc_$$TYPE
     DEFINES += QT_ATOMIC_FORCE_GCC

tests/auto/corelib/thread/qatomicinteger/qatomicinteger.pro

@@ -19,22 +19,22 @@ SUBDIRS=\
 
 
 contains(QT_CONFIG, c++11)|msvc: SUBDIRS +=\
-    cxx11/char \
-    cxx11/char16_t \
-    cxx11/char32_t \
-    cxx11/int \
-    cxx11/long \
-    cxx11/qlonglong \
-    cxx11/qptrdiff \
-    cxx11/quintptr \
-    cxx11/qulonglong \
-    cxx11/schar \
-    cxx11/short \
-    cxx11/uchar \
-    cxx11/uint \
-    cxx11/ulong \
-    cxx11/ushort \
-    cxx11/wchar_t \
+    no-cxx11/char \
+    no-cxx11/char16_t \
+    no-cxx11/char32_t \
+    no-cxx11/int \
+    no-cxx11/long \
+    no-cxx11/qlonglong \
+    no-cxx11/qptrdiff \
+    no-cxx11/quintptr \
+    no-cxx11/qulonglong \
+    no-cxx11/schar \
+    no-cxx11/short \
+    no-cxx11/uchar \
+    no-cxx11/uint \
+    no-cxx11/ulong \
+    no-cxx11/ushort \
+    no-cxx11/wchar_t \
 
 
 # The GCC-style atomics only support 32-bit and pointer-sized but add