code: public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
                                          Type site,
                                          List<Type> argtypes,
                                          List<Type> typeargtypes) {
          MethodResolutionContext resolveContext = new MethodResolutionContext();
          resolveContext.internalResolution = true;
          Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
          if (sym.kind == MTH) return (MethodSymbol)sym;
          else throw new FatalError(
                   diags.fragment("fatal.err.cant.locate.ctor", site));
      }
docs: Resolve a constructor, throw a fatal error if not found.
  @param pos       The position to use for error reporting.
  @param env       The environment current at the method invocation.
  @param site      The type to be constructed.
  @param argtypes  The types of the invocation's value arguments.
  @param typeargtypes  The types of the invocation's type arguments.