Check for 'long long' without computing size

In KWSys IOStream we need to detect whether 'long long' exists but we do
not need its size.  We avoid using CHECK_TYPE_SIZE because it does not
work for types whose size varies across architectuers in Mac OS X
universal binaries.  See issue #9913.

CMakeLists.txt

@@ -534,8 +534,9 @@ ENDIF(KWSYS_USE_FundamentalType)
 
 IF(KWSYS_USE_IOStream)
   # Determine whether iostreams support long long.
-  CHECK_TYPE_SIZE("long long" KWSYS_SIZEOF_LONG_LONG)
-  IF(KWSYS_SIZEOF_LONG_LONG)
+  KWSYS_PLATFORM_CXX_TEST(KWSYS_CXX_HAS_LONG_LONG
+    "Checking whether C++ compiler has 'long long'" DIRECT)
+  IF(KWSYS_CXX_HAS_LONG_LONG)
     SET(KWSYS_PLATFORM_CXX_TEST_DEFINES
       -DKWSYS_IOS_USE_ANSI=${KWSYS_IOS_USE_ANSI}
       -DKWSYS_IOS_HAVE_STD=${KWSYS_IOS_HAVE_STD})
@@ -544,10 +545,10 @@ IF(KWSYS_USE_IOStream)
     KWSYS_PLATFORM_CXX_TEST(KWSYS_IOS_HAS_OSTREAM_LONG_LONG
       "Checking if ostream supports long long" DIRECT)
     SET(KWSYS_PLATFORM_CXX_TEST_DEFINES)
-  ELSE(KWSYS_SIZEOF_LONG_LONG)
+  ELSE()
     SET(KWSYS_IOS_HAS_ISTREAM_LONG_LONG 0)
     SET(KWSYS_IOS_HAS_OSTREAM_LONG_LONG 0)
-  ENDIF(KWSYS_SIZEOF_LONG_LONG)
+  ENDIF()
 ENDIF(KWSYS_USE_IOStream)
 
 IF(KWSYS_NAMESPACE MATCHES "^kwsys$")

kwsysPlatformTestsCXX.cxx

@@ -113,6 +113,15 @@ void f(size_t) {}
 int main() { return 0; }
 #endif
 
+#ifdef TEST_KWSYS_CXX_HAS_LONG_LONG
+long long f(long long n) { return n; }
+int main()
+{
+  long long n = 0;
+  return static_cast<int>(f(n));
+}
+#endif
+
 #ifdef TEST_KWSYS_CXX_HAS_NULL_TEMPLATE_ARGS
 template <class T> class A;
 template <class T> int f(A<T>&);