C++: Parse __alignof__

Change-Id: I093c2a786cf8f10de4f05c23f3763ef1300feabd
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/libs/3rdparty/cplusplus/Keywords.cpp

@@ -1324,6 +1324,22 @@ static inline int classify11(const char *s, LanguageFeatures features)
               }
             }
           }
+        } else if (s[3] == 'l') {
+          if (s[4] == 'i') {
+            if (s[5] == 'g') {
+              if (s[6] == 'n') {
+                if (s[7] == 'o') {
+                  if (s[8] == 'f') {
+                    if (s[9] == '_') {
+                      if (s[10] == '_') {
+                        return T___ALIGNOF__;
+                      }
+                    }
+                  }
+                }
+              }
+            }
+          }
         }
       }
     }

src/libs/3rdparty/cplusplus/Token.h

@@ -286,6 +286,7 @@ enum Kind {
     T___VOLATILE__ = T_VOLATILE,
 
     T___ATTRIBUTE = T___ATTRIBUTE__,
+    T___ALIGNOF__ = T_ALIGNOF,
     T_LAST_TOKEN
 };