Remove Function.getACallExpr.

ql/src/RedundantCode/NegativeLengthCheck.ql

@@ -16,7 +16,7 @@ where
   (len = Builtin::len() or len = Builtin::cap()) and
   (
     exists(RelationalComparisonExpr rel | rel = cmp |
-      rel.getLesserOperand() = len.getACallExpr() and
+      rel.getLesserOperand() = len.getACall().asExpr() and
       rel.getGreaterOperand().getIntValue() = ub and
       (
         ub < 0
@@ -27,7 +27,7 @@ where
     )
     or
     exists(EqualityTestExpr eq | eq = cmp |
-      eq.getAnOperand() = len.getACallExpr() and
+      eq.getAnOperand() = len.getACall().asExpr() and
       eq.getAnOperand().getIntValue() = ub and
       ub < 0 and
       r = "equal"

ql/src/semmle/go/Expr.qll

@@ -464,7 +464,7 @@ class CallExpr extends CallOrConversionExpr {
   }
 
   /** Gets the declared target of this call. */
-  Function getTarget() { this = result.getACallExpr() }
+  Function getTarget() { getCalleeExpr() = result.getAReference() }
 
   override predicate mayHaveOwnSideEffects() {
     getTarget().mayHaveSideEffects() or

ql/src/semmle/go/Scopes.qll

@@ -276,9 +276,6 @@ class Field extends Variable {
 
 /** A built-in or declared function. */
 class Function extends ValueEntity, @functionobject {
-  /** Gets an expression representing a call to this function. */
-  CallExpr getACallExpr() { result.getCalleeExpr() = getAReference() }
-
   /** Gets a call to this function. */
   DataFlow::CallNode getACall() {
     this = result.getTarget()