Replace hasLocationInfo with getLocation in API::Node

Author: hvitved

ql/lib/codeql/Locations.qll

@@ -59,3 +59,8 @@ class Location extends @location {
     this.getStartLine() = other.getStartLine() and this.getStartColumn() < other.getStartColumn()
   }
 }
+
+/** An entity representing an empty location. */
+class EmptyLocation extends Location {
+  EmptyLocation() { this.hasLocationInfo("", 0, 0, 0, 0) }
+}

ql/lib/codeql/ruby/ApiGraphs.qll

@@ -140,26 +140,14 @@ module API {
      */
     DataFlow::Node getInducingNode() { this = Impl::MkUse(result) }
 
-    /**
-     * Holds if this element is at the specified location.
-     * The location spans column `startcolumn` of line `startline` to
-     * column `endcolumn` of line `endline` in file `filepath`.
-     * For more information, see
-     * [Locations](https://help.semmle.com/QL/learn-ql/locations.html).
-     */
-    predicate hasLocationInfo(
-      string filepath, int startline, int startcolumn, int endline, int endcolumn
-    ) {
-      getInducingNode().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+    /** Gets the location of this node. */
+    Location getLocation() {
+      result = this.getInducingNode().getLocation()
       or
       // For nodes that do not have a meaningful location, `path` is the empty string and all other
       // parameters are zero.
       not exists(getInducingNode()) and
-      filepath = "" and
-      startline = 0 and
-      startcolumn = 0 and
-      endline = 0 and
-      endcolumn = 0
+      result instanceof EmptyLocation
     }
 
     /**