C#: Fixup of locations to avoid antijoin.

Author: michaelnebel

csharp/ql/lib/semmle/code/csharp/Callable.qll

@@ -266,11 +266,7 @@ class Method extends Callable, Virtualizable, Attributable, @method {
   }
 
   override Location getALocation() {
-    exists(Method m | m = this.getUnboundDeclaration() |
-      method_location(m, result)
-      or
-      not method_location(m, _) and result instanceof EmptyLocation
-    )
+    exists(Method m | m = this.getUnboundDeclaration() | method_location(m, result))
   }
 
   /** Holds if this method is an extension method. */
@@ -363,11 +359,7 @@ class Constructor extends Callable, Member, Attributable, @constructor {
 
   override Constructor getUnboundDeclaration() { constructors(this, _, _, result) }
 
-  override Location getALocation() {
-    constructor_location(this, result)
-    or
-    not constructor_location(this, _) and result instanceof EmptyLocation
-  }
+  override Location getALocation() { constructor_location(this, result) }
 
   override predicate fromSource() { Member.super.fromSource() and not this.isCompilerGenerated() }