}

	return flags.Parse(strings.Fields(string(src[:end])))
}

// testFiles type-checks the package consisting of the given files, and
// compares the resulting errors with the ERROR annotations in the source.
// Except for manual tests, each package is type-checked twice, once without
// use of Alias types, and once with Alias types.
//
// The srcs slice contains the file content for the files named in the

	rclause = nil

	// Everything from here on is shared between cmd/compile/internal/types2 and go/types.

	// check expression to iterate over
	var x operand
	check.expr(nil, &x, rangeVar)

	// determine key/value types
	var key, val Type
	if x.mode != invalid {
		// Ranging over a type parameter is permitted if it has a core type.
		k, v, cause, isFunc, ok := rangeKeyVal(x.typ, func(v goVersion) bool {

	}

	// V must also be in the set of types of T, if any.
	// Constraints with empty type sets were already excluded above.
	if !Ti.typeSet().hasTerms() {
		return checkComparability() // nothing to do
	}

	// If V is itself an interface, each of its possible types must be in the set
	// of T types (i.e., the V type set must be a subset of the T type set).
	// Interfaces V with empty type sets were already excluded above.

func newAliasTypeName(pos token.Pos, pkg *types.Package, name string, rhs types.Type) *types.TypeName {
	// When GODEBUG=gotypesalias=1 or unset, the Type() of the return value is a
	// *types.Alias. Copied from x/tools/internal/aliases.NewAlias.
	switch godebug.New("gotypesalias").Value() {
	case "", "1":
		tname := types.NewTypeName(pos, pkg, name, nil)
		_ = types.NewAlias(tname, rhs) // form TypeName -> Alias cycle

// identical.
func identicalInstance(xorig Type, xargs []Type, yorig Type, yargs []Type) bool {
	if len(xargs) != len(yargs) {
		return false
	}

	for i, xa := range xargs {
		if !Identical(xa, yargs[i]) {
			return false
		}
	}

	return Identical(xorig, yorig)
}

// Default returns the default "typed" type for an "untyped" type;

// predeclared types, defined types, and type parameters.
// hasName may be called with types that are not fully set up.
func hasName(t Type) bool {
	switch Unalias(t).(type) {
	case *Basic, *Named, *TypeParam:
		return true
	}
	return false
}

// isTypeLit reports whether t is a type literal.
// This includes all non-defined types, but also basic types.

			return false
		}
		// Any user-defined type name for a basic type is an alias for a
		// basic type (because basic types are pre-declared in the Universe
		// scope, outside any package scope), and so is any type name with
		// a different name than the name of the basic type it refers to.
		// Additionally, we need to look for "byte" and "rune" because they
		// are aliases but have the same names (for better error messages).

			return false
		}
		// Any user-defined type name for a basic type is an alias for a
		// basic type (because basic types are pre-declared in the Universe
		// scope, outside any package scope), and so is any type name with
		// a different name than the name of the basic type it refers to.
		// Additionally, we need to look for "byte" and "rune" because they
		// are aliases but have the same names (for better error messages).

	recvTParamMap map[*ast.Ident]*TypeParam // maps blank receiver type parameters to their type
	brokenAliases map[*TypeName]bool        // set of aliases with broken (not yet determined) types
	unionTypeSets map[*Union]*_TypeSet      // computed type sets for union types
	mono          monoGraph                 // graph for detecting non-monomorphizable instantiation loops

func containsNil(list []Type) bool {
	for _, t := range list {
		if t == nil {
			return true
		}
	}
	return false
}

// renameTParams renames the type parameters in the given type such that each type
// parameter is given a new identity. renameTParams returns the new type parameters
// and updated type. If the result type is unchanged from the argument type, none