Rust: Check call arities in path resolution

rust/ql/lib/codeql/rust/controlflow/internal/ControlFlowGraphImpl.qll

@@ -77,7 +77,7 @@ class CallableScopeTree extends StandardTree, PreOrderTree, PostOrderTree, Scope
 
   override AstNode getChildNode(int i) {
     i = 0 and
-    result = this.getParamList().getSelfParam()
+    result = this.getSelfParam()
     or
     result = this.getParam(i - 1)
     or

rust/ql/lib/codeql/rust/elements/internal/CallImpl.qll

@@ -102,7 +102,7 @@ module Impl {
       f = resolvePath(path) and
       path.getSegment().getIdentifier().getText() = methodName and
       exists(SelfParam self |
-        self = f.getParamList().getSelfParam() and
+        self = f.getSelfParam() and
         if self.isRef() then selfIsRef = true else selfIsRef = false
       )
     )

rust/ql/lib/codeql/rust/elements/internal/CallableImpl.qll

@@ -17,5 +17,15 @@ module Impl {
    */
   class Callable extends Generated::Callable {
     override Param getParam(int index) { result = this.getParamList().getParam(index) }
+
+    /**
+     * Gets the self parameter of this callable, if it exists.
+     */
+    SelfParam getSelfParam() { result = this.getParamList().getSelfParam() }
+
+    /**
+     * Holds if `getSelfParam()` exists.
+     */
+    predicate hasSelfParam() { exists(this.getSelfParam()) }
   }
 }

rust/ql/lib/codeql/rust/elements/internal/VariableImpl.qll

@@ -109,7 +109,7 @@ module Impl {
       text = name.getText() and
       // exclude self parameters from functions without a body as these are
       // trait method declarations without implementations
-      not exists(Function f | not f.hasBody() and f.getParamList().getSelfParam() = sp)
+      not exists(Function f | not f.hasBody() and f.getSelfParam() = sp)
     )
     or
     exists(IdentPat pat |

rust/ql/lib/codeql/rust/internal/CachedStages.qll

@@ -117,7 +117,7 @@ module Stages {
       or
       exists(resolvePath(_))
       or
-      exists(any(ItemNode i).getASuccessor(_, _))
+      exists(any(ItemNode i).getASuccessor(_, _, _))
       or
       exists(any(ImplOrTraitItemNode i).getASelfPath())
       or