Regions() []Region
}

var (
	// Supported defines a Coverage that lists all supported subtags. Tags
	// always returns nil.
	Supported Coverage = allSubtags{}
)

// TODO:
// - Support Variants, numbering systems.
// - CLDR coverage levels.
// - Set of common tags defined in this package.

type allSubtags struct{}

// Regions returns the list of supported regions. As all regions are in a

type Level int

// Names for common levels.
//
// Level numbers are inherently arbitrary,
// but we picked them to satisfy three constraints.
// Any system can map them to another numbering scheme if it wishes.
//
// First, we wanted the default level to be Info, Since Levels are ints, Info is
// the default value for int, zero.
//
// Second, we wanted to make it easy to use levels to specify logger verbosity.

		path, fname := cutLastDot(fr.Function)
		if path == lastImport {
			path = `"` // (a ditto mark)
		} else {
			lastImport = path
		}
		var loc string
		if fr.Func != nil {
			// Use function-relative line numbering.
			// f:+2 means two lines into function f.
			// f:-1 should never happen, but be conservative.
			_, entryLine := fr.Func.FileLine(fr.Entry)
			loc = fmt.Sprintf("%s.%s:%+d", path, fname, fr.Line-entryLine)
		} else {

A custom `message` allows explaining why the artifact coordinates have changed.
====

	s       *state                   // SSA state
	f       *ssa.Func                // function to work on
	defvars []map[ir.Node]*ssa.Value // defined variables at end of each block

	varnum map[ir.Node]int32 // variable numbering

	// properties of the dominator tree
	idom  []*ssa.Block // dominator parents
	tree  []domBlock   // dominator child+sibling

			break
		}
	}
	// Set idom of entry block to nil instead of itself.
	idom[f.Entry.ID] = nil
	return idom
}

// intersect finds the closest dominator of both b and c.
// It requires a postorder numbering of all the blocks.
func intersect(b, c *Block, postnum []int, idom []*Block) *Block {
	// TODO: This loop is O(n^2). It used to be used in nilcheck,
	// see BenchmarkNilCheckDeep*.
	for b != c {

	REG_F22
	REG_F23
	REG_F24
	REG_F25
	REG_F26
	REG_F27
	REG_F28
	REG_F29
	REG_F30
	REG_F31

	// This marks the end of the register numbering.
	REG_END

	// General registers reassigned to ABI names.
	REG_ZERO = REG_X0
	REG_RA   = REG_X1 // aka REG_LR
	REG_SP   = REG_X2
	REG_GP   = REG_X3 // aka REG_SB
	REG_TP   = REG_X4
	REG_T0   = REG_X5
	REG_T1   = REG_X6
	REG_T2   = REG_X7

  std::unique_ptr<ParallelTensor> ScalarsFromSequence(
      absl::Span<const DataType> values, TFE_Context* context,
      TF_Status* status) const;

  // A parallel tensor with scalar integers numbering component devices.
  std::unique_ptr<ParallelTensor> DeviceIDs(TFE_Context* context,
                                            TF_Status* status) const;

  // The number of devices operations run on.

	}
	return record, err
}

// FieldPos returns the line and column corresponding to
// the start of the field with the given index in the slice most recently
// returned by [Reader.Read]. Numbering of lines and columns starts at 1;
// columns are counted in bytes, not runes.
//
// If this is called with an out-of-bounds index, it panics.
func (r *Reader) FieldPos(field int) (line, column int) {

	body  *syntax.BlockStmt

	// References to important types and values.
	any   types2.Object
	bool  types2.Object
	int   types2.Object
	true  types2.Object
	false types2.Object

	// Branch numbering, computed as needed.
	branchNext map[branch]int             // branch -> #next value
	labelLoop  map[string]*syntax.ForStmt // label -> innermost rangefunc loop it is declared inside (nil for no loop)