Add support for boost sync objects (#6007)

Author: chrchr-github

cfg/boost.cfg

@@ -1267,4 +1267,17 @@
       <not-uninit/>
     </arg>
   </function>
+  <type-checks>
+    <unusedvar>
+      <checkFiniteLifetime>boost::lock_guard</checkFiniteLifetime>
+      <checkFiniteLifetime>boost::mutex::scoped_lock</checkFiniteLifetime>
+      <checkFiniteLifetime>boost::recursive_mutex::scoped_lock</checkFiniteLifetime>
+      <checkFiniteLifetime>boost::unique_lock</checkFiniteLifetime>
+      <checkFiniteLifetime>boost::shared_lock</checkFiniteLifetime>
+    </unusedvar>
+    <operatorEqVarError>
+      <suppress>boost::mutex</suppress>
+      <suppress>boost::recursive_mutex</suppress>
+    </operatorEqVarError>
+  </type-checks>
 </def>

test/cfg/boost.cpp

@@ -13,6 +13,8 @@
 #include <boost/bind.hpp>
 #include <boost/function.hpp>
 #include <boost/smart_ptr/scoped_array.hpp>
+#include <boost/thread/mutex.hpp>
+#include <boost/thread/lock_guard.hpp>
 
 BOOST_FORCEINLINE void boost_forceinline_test()
 {}
@@ -94,4 +96,10 @@ void containerOutOfBounds_scoped_array(std::size_t n) // #12356
     boost::scoped_array<int> d(new int[n] {});
     for (std::size_t i = 0; i < n; i++)
         if (d[i]) {}
+}
+
+void lock_guard_finiteLifetime(boost::mutex& m)
+{
+    // cppcheck-suppress unusedScopedObject
+    boost::lock_guard<boost::mutex>{ m };
 }