C#: Respect the context when extracting locations for type parameters and tuple typles.

csharp/extractor/Semmle.Extraction.CSharp/Extractor/Context.cs

@@ -554,6 +554,18 @@ namespace Semmle.Extraction.CSharp
             SymbolEqualityComparer.Default.Equals(symbol, symbol.OriginalDefinition) &&
             scope.InScope(symbol);
 
+        /// <summary>
+        /// Gets the locations of the symbol that are either
+        /// (1) In assemblies.
+        /// (2) In the current context.
+        /// </summary>
+        /// <param name="symbol">The symbol</param>
+        /// <returns>List of locations</returns>
+        public IEnumerable<Entities.Location> GetLocations(ISymbol symbol) =>
+            symbol.Locations
+                .Where(l => !l.IsInSource || IsLocationInContext(l))
+                .Select(CreateLocation);
+
         public bool IsLocationInContext(Location location) =>
             location.SourceTree == SourceTree;