add test, fix review comments

Author: danmar

lib/token.h

@@ -555,7 +555,7 @@ class CPPCHECKLIB Token {
         setFlag(fIsAttributeMaybeUnused, value);
     }
     std::vector<std::string> getAttributeAlignas() const {
-        return !mImpl->mAttributeAlignas ? std::vector<std::string>() : *mImpl->mAttributeAlignas;
+        return mImpl->mAttributeAlignas ? *mImpl->mAttributeAlignas : std::vector<std::string>();
     }
     bool hasAttributeAlignas() const {
         return !!mImpl->mAttributeAlignas;

lib/tokenize.cpp

@@ -6048,6 +6048,7 @@ void Tokenizer::dump(std::ostream &out) const
             const std::vector<std::string>& a = tok->getAttributeAlignas();
             outs += " alignas=\"" + ErrorLogger::toxml(a[0]) + "\"";
             if (a.size() > 1)
+                // we could write all alignas expressions but currently we only need 2
                 outs += " alignas2=\"" + ErrorLogger::toxml(a[1]) + "\"";
         }
         if (tok->link()) {

test/testtokenize.cpp

@@ -439,6 +439,7 @@ class TestTokenizer : public TestFixture {
 
         TEST_CASE(removeAlignas1);
         TEST_CASE(removeAlignas2); // Do not remove alignof in the same way
+        TEST_CASE(dumpAlignas);
 
         TEST_CASE(simplifyCoroutines);
 
@@ -7850,6 +7851,17 @@ class TestTokenizer : public TestFixture {
         ASSERT_EQUALS(expected, tokenizeAndStringify(code));
     }
 
+    void dumpAlignas() {
+        Settings settings;
+        SimpleTokenizer tokenizer(settings, *this);
+        tokenizer.tokenize("int alignas(8) alignas(16) x;", false);
+        ASSERT(Token::simpleMatch(tokenizer.tokens(), "int x ;"));
+        std::ostringstream ostr;
+        tokenizer.dump(ostr);
+        const std::string dump = ostr.str();
+        ASSERT(dump.find(" alignas=\"8\" alignas2=\"16\"") != std::string::npos);
+    }
+
     void simplifyCoroutines() {
         const Settings settings = settingsBuilder().cpp(Standards::CPP20).build();