C++: fix hasImplicitCopyConstructor for templates

Fixes some cases in instantiations of templates with manually written
copy constructors or copy assignment operators where
hasImplicitCopyConstructor would incorrectly hold

Author: rdmarsh2

cpp/ql/lib/semmle/code/cpp/Class.qll

@@ -286,6 +286,16 @@ class Class extends UserType {
     not this.implicitCopyConstructorDeleted() and
     forall(CopyConstructor cc | cc = this.getAMemberFunction() |
       cc.isCompilerGenerated() and not cc.isDeleted()
+    ) and
+    (
+      not this instanceof ClassTemplateInstantiation
+      or
+      this.(ClassTemplateInstantiation).getTemplate().hasImplicitCopyConstructor()
+    ) and
+    (
+      not this instanceof PartialClassTemplateSpecialization
+      or
+      this.(PartialClassTemplateSpecialization).getPrimaryTemplate().hasImplicitCopyConstructor()
     )
   }
 
@@ -301,6 +311,18 @@ class Class extends UserType {
     not this.implicitCopyAssignmentOperatorDeleted() and
     forall(CopyAssignmentOperator ca | ca = this.getAMemberFunction() |
       ca.isCompilerGenerated() and not ca.isDeleted()
+    ) and
+    (
+      not this instanceof ClassTemplateInstantiation
+      or
+      this.(ClassTemplateInstantiation).getTemplate().hasImplicitCopyAssignmentOperator()
+    ) and
+    (
+      not this instanceof PartialClassTemplateSpecialization
+      or
+      this.(PartialClassTemplateSpecialization)
+          .getPrimaryTemplate()
+          .hasImplicitCopyAssignmentOperator()
     )
   }
 

cpp/ql/test/library-tests/special_members/generated_copy/ctor.expected

@@ -11,7 +11,7 @@
 | difference::Base | can | does NOT | have implicit copy constructor |
 | difference::OnlyAssign | can NOT | does NOT | have implicit copy constructor |
 | difference::OnlyCtor | can | does | have implicit copy constructor |
-| instantiated_explicit_ctor::Wrapper<int> | can | does | have implicit copy constructor |
+| instantiated_explicit_ctor::Wrapper<int> | can | does NOT | have implicit copy constructor |
 | moves::MoveAssign | can NOT | does NOT | have implicit copy constructor |
 | moves::MoveCtor | can NOT | does NOT | have implicit copy constructor |
 | private_cc::C | can | does NOT | have implicit copy constructor |