removed `TokenList::getSettings()` and replaced usage in ValueFlow with provided settings (#4843)

lib/tokenlist.cpp

@@ -1660,7 +1660,7 @@ struct OnException {
 void TokenList::validateAst() const
 {
     OnException oe{[&] {
-            if (mSettings->debugnormal)
+            if (mSettings && mSettings->debugnormal)
                 mTokensFrontBack.front->printOut();
         }};
     // Check for some known issues in AST to avoid crash/hang later on
@@ -1784,6 +1784,9 @@ bool TokenList::validateToken(const Token* tok) const
 
 void TokenList::simplifyPlatformTypes()
 {
+    if (!mSettings)
+        return;
+
     const bool isCPP11  = mSettings->standards.cpp >= Standards::CPP11;
 
     enum { isLongLong, isLong, isInt } type;

lib/tokenlist.h

@@ -50,10 +50,6 @@ public:
         mSettings = settings;
     }
 
-    const Settings *getSettings() const {
-        return mSettings;
-    }
-
     /** @return the source file path. e.g. "file.cpp" */
     const std::string& getSourceFilePath() const;