unified: Use start-line for detecting variable aliases

Author: asgerf

unified/ql/test/library-tests/variables/test.swift

@@ -343,11 +343,10 @@ enum E38 {
 }
 
 // Switch with a multi-pattern case that binds 'x' in each pattern
-// Note: the testing framework does not make it possible to name the 'x' variable in this case.
 func t38(value: E38) {
     switch value { // $ access=value
-    case .a(let x), // $ access=x
-         .b(let x): // $ access=x
-        print(x) // $ access=x
+    case .a(let x), // $ access=x1 // name=x1
+         .b(let x): // $ access=x1
+        print(x) // $ access=x1
     }
 }

unified/ql/test/library-tests/variables/variables.ql

@@ -25,6 +25,7 @@ module VariableAccessTest implements TestSig {
 
   private predicate declAt(Variable v, string filepath, int line) {
     v.getLocation().hasLocationInfo(filepath, _, _, line, _)
+    v.getLocation().hasLocationInfo(filepath, line, _, _, _)
   }
 
   private predicate decl(Variable v, string alias) {