Exclude typedefs from analysis

Author: MichaelRFairhurst

cpp/misra/src/rules/RULE-6-2-3/DuplicateTypeDefinitions.ql

@@ -20,7 +20,7 @@ import codingstandards.cpp.Linkage
 
 class UserTypeDefinition extends TypeDeclarationEntry {
   UserTypeDefinition() {
-    (isDefinition() or getDeclaration() instanceof TypedefType) and
+    isDefinition() and
     not getDeclaration().(Class).isAnonymous() and
     not getDeclaration().(Union).isAnonymous() and
     not getDeclaration().(Enum).isAnonymous() and

cpp/misra/test/rules/RULE-6-2-3/test.cpp

@@ -27,8 +27,8 @@ template <typename T> class TplRedeclared {}; // COMPLIANT
 enum DuplicateEnum {};            // NON_COMPLIANT
 enum class DuplicateEnumClass {}; // NON_COMPLIANT
 enum {} anonymousEnum1;           // COMPLIANT
-typedef int16_t DuplicateTypedef; // NON_COMPLIANT
-using DuplicateUsing = int16_t;   // NON_COMPLIANT
+typedef int16_t DuplicateTypedef; // COMPLIANT -- Redeclared typedefs are OK
+using DuplicateUsing = int16_t;   // COMPLIANT -- Redeclared type aliases are OK
 union DuplicateUnion {};          // NON_COMPLIANT
 union {
 } anonymousUnion1; // COMPLIANT