Update cpp/ql/lib/semmle/code/cpp/Function.qll

Co-authored-by: Jeroen Ketema <93738568+jketema@users.noreply.github.com>

Author: calumgrant

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

@@ -651,9 +651,8 @@ class FunctionDeclarationEntry extends DeclarationEntry, @fun_decl {
 
   /**
    * Holds if this declaration is an implicit function declaration, that is,
-   * where a function is used before it is declared (under older C standards).
-   * This can also happen in standalone extraction when a function has not been
-   * properly declared.
+   * where a function is used before it is declared (under older C standards,
+   * or when there were parse errors).
    */
   predicate isImplicit() { fun_implicit(underlyingElement(this)) }