Improved generator tracking

* Successive executions of the same `GENERATE` macro (e.g. because
of a for loop) no longer lead to multiple nested generators.
* The same line can now contain multiple `GENERATE` macros without
issues.

Fixes #1913

include/internal/catch_test_case_tracker.h

@@ -23,6 +23,10 @@ namespace TestCaseTracking {
         SourceLineInfo location;
 
         NameAndLocation( std::string const& _name, SourceLineInfo const& _location );
+        friend bool operator==(NameAndLocation const& lhs, NameAndLocation const& rhs) {
+            return lhs.name == rhs.name
+                && lhs.location == rhs.location;
+        }
     };
 
     struct ITracker;