Don't test for old compilers in C++11 mode in configure

This makes configure faster when C++11 is enabled by avoiding spending time on
compiling unnecessary checks in this case.

include/wx/defs.h

@@ -340,7 +340,9 @@ typedef short int WXTYPE;
 #define wxConstCast(obj, className) wx_const_cast(className *, obj)
 
 #ifndef HAVE_STD_WSTRING
-    #if defined(__VISUALC__)
+    #if __cplusplus >= 201103L
+        #define HAVE_STD_WSTRING
+    #elif defined(__VISUALC__)
         #define HAVE_STD_WSTRING
     #elif defined(__MINGW32__)
         #define HAVE_STD_WSTRING
@@ -348,7 +350,9 @@ typedef short int WXTYPE;
 #endif
 
 #ifndef HAVE_STD_STRING_COMPARE
-    #if defined(__VISUALC__)
+    #if __cplusplus >= 201103L
+        #define HAVE_STD_STRING_COMPARE
+    #elif defined(__VISUALC__)
         #define HAVE_STD_STRING_COMPARE
     #elif defined(__MINGW32__) || defined(__CYGWIN32__)
         #define HAVE_STD_STRING_COMPARE

include/wx/wxcrtbase.h

@@ -183,6 +183,16 @@ extern unsigned long android_wcstoul(const wchar_t *nptr, wchar_t **endptr, int
     #define wxCRT_StrtollW   _wcstoi64
     #define wxCRT_StrtoullW  _wcstoui64
 #else
+    /* Both of these functions are implemented in C++11 compilers */
+    #if defined(__cplusplus) && __cplusplus >= 201103L
+        #ifndef HAVE_STRTOULL
+            #define HAVE_STRTOULL
+        #endif
+        #ifndef HAVE_WCSTOULL
+            #define HAVE_WCSTOULL
+        #endif
+    #endif
+
     #ifdef HAVE_STRTOULL
         #define wxCRT_StrtollA   strtoll
         #define wxCRT_StrtoullA  strtoull