Honor library ignorefunction() settings when reporting unused functions.

This change updates CheckUnusedFunctions to skip functions explicitly
marked as ignored by the library configuration, both during per-file
checks and whole-program analysis. This prevents false positives for
known framework hooks, callbacks, or externally-used symbols that should
be intentionally excluded from unused-function diagnostics.

Signed-off-by: Robin Getz <rgetz503@gmail.com>

Author: rgetz

lib/checkunusedfunctions.cpp

@@ -378,6 +378,8 @@ bool CheckUnusedFunctions::check(const Settings& settings, ErrorLogger& errorLog
             continue;
         if (settings.library.isentrypoint(it->first))
             continue;
+        if (settings.library.ignorefunction(it->first))
+            continue;
         if (!func.usedSameFile) {
             if (isOperatorFunction(it->first))
                 continue;
@@ -490,6 +492,9 @@ void CheckUnusedFunctions::analyseWholeProgram(const Settings &settings, ErrorLo
         if (settings.library.isentrypoint(functionName))
             continue;
 
+	if (settings.library.ignorefunction(functionName))
+            continue;
+
         if (calls.find(functionName) == calls.end() && !isOperatorFunction(functionName)) {
             const Location &loc = decl->second;
             unusedFunctionError(errorLogger, loc.fileName, /*fileIndex*/ 0, loc.lineNumber, loc.column, functionName);