Fix #13495 #13499 Fuzzing crashes (danmar#7159)

Author: chrchr-github

lib/tokenize.cpp

@@ -8736,6 +8736,8 @@ void Tokenizer::findGarbageCode() const
             syntaxError(tok);
         if (Token::Match(tok, "; %assign%"))
             syntaxError(tok);
+        if (Token::Match(tok, "%assign% %name%") && tok->next()->isControlFlowKeyword())
+            syntaxError(tok);
         if (Token::Match(tok, "%cop%|=|,|[ %or%|%oror%|/|%"))
             syntaxError(tok);
         if (Token::Match(tok, "[;([{] %comp%|%oror%|%or%|%|/"))
@@ -8841,6 +8843,8 @@ void Tokenizer::findGarbageCode() const
                     syntaxError(tok);
             }
         }
+        if (cpp && tok->str() == "using" && !Token::Match(tok->next(), "::|%name%"))
+            syntaxError(tok);
     }
 
     // ternary operator without :

test/cli/fuzz-crash/crash-ee5250480d7bc4bed7520d96a50d8501632a8997

@@ -0,0 +1 @@
+$(){using}

test/cli/fuzz-crash_c/crash-dd1289f81f5aaf90167595c5402e6cda2be505be

@@ -0,0 +1 @@
+d(){A a;n=do{}while(N)t}