//
	// Example:
	//  var _ = complex(float32(1), float64(2))
	InvalidComplex

	// InvalidDelete occurs when the delete built-in function is called with a
	// first argument that is not a map.
	//
	// Example:
	//  func f() {
	//  	m := "hello"
	//  	delete(m, "e")
	//  }
	InvalidDelete

	// InvalidImag occurs when the imag built-in function is called with an

	// Checker.resolveBaseTypeName ensures that obj is not an alias name
	// if it has attached methods.)
	methods := check.methods[obj]
	if methods == nil {
		return
	}
	delete(check.methods, obj)
	assert(!check.objMap[obj].tdecl.Alias) // don't use TypeName.IsAlias (requires fully set up object)

	// use an objset to check for name conflicts
	var mset objset

		canDashC = false
	case "1":
		canDashC = true
	case "":
		// Not set. Use default.
	default:
		log.Fatalf("GO19CONCURRENTCOMPILATION must be 0, 1, or unset, got %q", e)
	}

	// TODO: Test and delete these conditions.
	if cfg.ExperimentErr != nil || cfg.Experiment.FieldTrack || cfg.Experiment.PreemptibleLoops {
		canDashC = false
	}

	if !canDashC {
		return 1
	}

	alias.typ = Typ[Invalid]
}

// validAlias records that alias has the valid type typ (possibly Typ[Invalid]).
func (check *Checker) validAlias(alias *TypeName, typ Type) {
	assert(!check.conf._EnableAlias)
	delete(check.brokenAliases, alias)
	alias.typ = typ
}

// isBrokenAlias reports whether alias doesn't have a determined type yet.
func (check *Checker) isBrokenAlias(alias *TypeName) bool {

	procs.Lock()
	ch := procs.waits[pid]
	procs.Unlock()

	var wmsg *waitErr
	if ch != nil {
		wmsg = <-ch
		procs.Lock()
		if procs.waits[pid] == ch {
			delete(procs.waits, pid)
		}
		procs.Unlock()
	}
	if wmsg == nil {
		// ch was missing or ch is closed
		return NewError("process not found")
	}
	if wmsg.err != nil {
		return wmsg.err
	}

	// because state.vars has been reset by the preceding state.startBlock.
	// They only enforce the fact that these variables are no longer need in
	// the current scope.
	delete(s.vars, ptrVar)
	delete(s.vars, lenVar)
	if !inplace {
		delete(s.vars, capVar)
	}

	// make result
	if inplace {
		return nil
	}
	return s.newValue3(ssa.OpSliceMake, n.Type(), p, l, c)
}

	}

	return b
}

var builderWorkDirs sync.Map // *Builder → WorkDir

func (b *Builder) Close() error {
	wd, ok := builderWorkDirs.Load(b)
	if !ok {
		return nil
	}
	defer builderWorkDirs.Delete(b)

	if b.WorkDir != wd.(string) {
		base.Errorf("go: internal error: Builder WorkDir unexpectedly changed from %s to %s", wd, b.WorkDir)
	}

	if !cfg.BuildWork {

	if coalescesUp && coalescesDown {
		// We have neighbors and they both border us.
		// Merge a.ranges[i-1], r, and a.ranges[i] together into a.ranges[i-1].
		a.ranges[i-1].limit = a.ranges[i].limit

		// Delete a.ranges[i].
		copy(a.ranges[i:], a.ranges[i+1:])
		a.ranges = a.ranges[:len(a.ranges)-1]
	} else if coalescesDown {
		// We have a neighbor at a lower address only and it borders us.

	// exists in the Request.Header map but has a nil value
	// (such as when set by the Director func), the X-Forwarded-For
	// header is not modified.
	//
	// To prevent IP spoofing, be sure to delete any pre-existing
	// X-Forwarded-For header coming from the client or
	// an untrusted proxy.
	//
	// Hop-by-hop headers are removed from the request after
	// Director returns, which can remove headers added by

				Name:       "file2",
				PAXRecords: map[string]string{"path": "file2"},
			}, nil},
			testHeader{Header{
				Typeflag:   TypeXGlobalHeader,
				PAXRecords: map[string]string{"path": ""}, // Should delete "path", but keep "mtime"
			}, nil},
			testHeader{Header{
				Typeflag: TypeReg, Name: "file3",
			}, nil},
			testHeader{Header{
				Typeflag:   TypeReg,
				Name:       "file4",