pNew := &bNew[cap(bNew)-1]
	if flags&mremapDontunmap == 0 {
		delete(m.active, pOld)
	}
	m.active[pNew] = bNew
	return bNew, nil
}

func Mremap(oldData []byte, newLength int, flags int) (data []byte, err error) {
	return mapper.Mremap(oldData, newLength, flags)

//sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
//sys	sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)
//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)
//sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
//sys	mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error)

			}

			return EmitCollateral(root, &c)
		},
	}

	cmd.Flags().StringVarP(&c.OutputDir, "outputDir", "o", c.OutputDir, "Directory where to generate the collateral files")
	cmd.Flags().BoolVarP(&all, "all", "", all, "Produce all supported collateral files")
	cmd.Flags().BoolVarP(&c.EmitMarkdown, "markdown", "", c.EmitMarkdown, "Produce markdown documentation files")
	cmd.Flags().BoolVarP(&c.EmitManPages, "man", "", c.EmitManPages, "Produce man pages")

	testenv.MustHaveExec(t)

	testCases := []struct {
		desc  string
		flags []string
		want  string
	}{{
		desc:  "root test panics",
		flags: []string{"-test_panic_test=TestPanicHelper"},
		want: `
--- FAIL: TestPanicHelper (N.NNs)
    panic_test.go:NNN: TestPanicHelper
`,
	}, {
		desc:  "subtest panics",
		flags: []string{"-test_panic_test=TestPanicHelper/1"},
		want: `
--- FAIL: TestPanicHelper (N.NNs)

	flags = _SigNotify
	for sig, t = range sigtable {
		if stringslite.HasPrefix(notestr, t.name) {
			flags = t.flags
			break
		}
	}
	if flags&_SigPanic != 0 && gp.throwsplit {
		// We can't safely sigpanic because it may grow the
		// stack. Abort in the signal handler instead.
		flags = (flags &^ _SigPanic) | _SigThrow
	}
	if flags&_SigGoExit != 0 {

//sysnb	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
//sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
//sys	sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)
//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)
//sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)

//sys	futimesat(dirfd int, path string, times *[2]Timeval) (err error)

func (sym *Sym) Siggen() bool       { return sym.flags&symSiggen != 0 }
func (sym *Sym) Asm() bool          { return sym.flags&symAsm != 0 }
func (sym *Sym) Func() bool         { return sym.flags&symFunc != 0 }

func (sym *Sym) SetOnExportList(b bool) { sym.flags.set(symOnExportList, b) }
func (sym *Sym) SetUniq(b bool)         { sym.flags.set(symUniq, b) }
func (sym *Sym) SetSiggen(b bool)       { sym.flags.set(symSiggen, b) }

  write_graph(tfadd, FLAGS.out_dir)
  write_graph(tfadd_with_ckpt, FLAGS.out_dir)
  write_graph(tfadd_with_ckpt_saver, FLAGS.out_dir)
  write_graph(tfassert_eq, FLAGS.out_dir)
  write_graph(tfcond, FLAGS.out_dir)
  write_graph(tffunction, FLAGS.out_dir)
  write_graph(tfgather, FLAGS.out_dir)
  write_graph(tfmatmul, FLAGS.out_dir)
  write_graph(tfmatmulandadd, FLAGS.out_dir)
  write_graph(tfsplits, FLAGS.out_dir)

//sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
//sys	sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)
//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)
//sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
//sys	mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error)

	(?<name>re)    named & numbered capturing group (submatch)
	(?:re)         non-capturing group
	(?flags)       set flags within current group; non-capturing
	(?flags:re)    set flags during re; non-capturing

	Flag syntax is xyz (set) or -xyz (clear) or xy-z (set xy, clear z). The flags are:

	i              case-insensitive (default false)