Fix extern c typedef syntax error (#2438)

* Fix extern c typedef syntax error

* Fix extraWhiteSpaceError

* Move test from testgarbage to testtokenize

Author: RobkeBaer

lib/tokenize.cpp

@@ -9346,7 +9346,8 @@ void Tokenizer::findGarbageCode() const
         while (prev && prev->isName())
             prev = prev->previous();
         if (Token::Match(prev, "%op%|%num%|%str%|%char%")) {
-            if (!Token::simpleMatch(tok->tokAt(-2), "operator \"\" if"))
+            if (!Token::simpleMatch(tok->tokAt(-2), "operator \"\" if") &&
+		 !Token::simpleMatch(tok->tokAt(-2), "extern \"C\"")  )
                 syntaxError(tok, prev == tok->previous() ? (prev->str() + " " + tok->str()) : (prev->str() + " .. " + tok->str()));
         }
     }

test/testtokenize.cpp

@@ -7959,6 +7959,8 @@ class TestTokenizer : public TestFixture {
 
         ASSERT_NO_THROW(tokenizeAndStringify("S s = { .x=2, .y[0]=3 };"));
         ASSERT_NO_THROW(tokenizeAndStringify("S s = { .ab.a=2, .ab.b=3 };"));
+
+        ASSERT_NO_THROW(tokenizeAndStringify("extern \"C\" typedef void FUNC();"));
     }