v3.11.0

The editor replaces, and two things it shipped broken a day ago do not do
that any more. v3.10.0 put eight documents behind one screen in a day, and
two questions that had been complete became incomplete without changing: the
quit guard asked about the document on screen, so Ctrl-Q over a clean one
discarded another's work in silence; and the menu's key dispatch did not name
the two kinds that feature had added, so F3 or F6 with the menu open stopped
the program. Both are fixed, and the gate that could have caught the second is
now pointed at every program here instead of only at the compiler.

Added

• The editor replaces. Ctrl-R asks for a pattern and a replacement and
  changes every occurrence in the document, matching case-insensitively as the
  search does, with an empty replacement meaning deletion — and one Ctrl-Z
  takes the whole of it back (ADR-0403). Search ▸ Replace is the same thing
  from the menu. That last part is why it is not a small feature: the undo
  journal knew about operations and not about actions, so an entry may
  now say the undo continues through it — a property of an entry, deliberately
  not a fifth operation, so the four routines are still the only code that
  touches the buffer. Confirm-each was rejected rather than deferred: what a
  person wants after a replace that went wrong is to undo it.
• Every program here is checked for a case that has stopped covering its
  enumeration, not only the compiler (ADR-0404). The editor and the language
  server join the sweep — five corpora, and adding one is a line — because
  --dump-dispatch answers that question about any Pascal program and had
  been asked about one. 63 case-statements over 13 enumerations became 79 over
  35. The crash below is what the widening found.
• The editor's shell is checked. tui-terminal drives the real editor
  under a pseudo-terminal and requires every coloured run it writes to be one
  the model decided, at the same columns, in the colour that role's table
  gives, over both the twenty-four-bit and the eight-colour table (ADR-0402).
  Nothing had ever read a byte the editor wrote to a terminal: a shell
  painting every row in one flat colour passed every oracle here. The
  expectation is derived from the session golden's own run decomposition
  rather than recorded.

Changed

• The runtime's POSIX half is two translation units. What the operating
  system is asked about — a file's size and kind, a directory's entries,
  whether a descriptor has anything to read — is now runtime/pasrt_file.c,
  and what it is asked to do — a process, a socket, a terminal, a private
  directory — stays in runtime/pasrt_posix.c (ADR-0405). Nothing a program
  can call changed; what changed is that a target with a file system and no
  processes gets the first half, which is what wasm32-wasi is. 560 of the
  598 corpus programs ran there and 563 do.

Fixed

• The editor no longer discards another document's changes on one Ctrl-Q.
  Since eight documents landed in v3.10.0, the quit guard asked whether the
  document on screen was modified, so typing into one file, opening a clean
  second over it and pressing Ctrl-Q once exited with no prompt and no
  message. It now asks about every open document and the message says how many
  hold changes (ADR-0401). Two presses still discard, as they always have.
• F3 and F6 no longer stop the editor when the menu is open. MenuKey
  dispatches over the key kinds with a case and no otherwise — the right
  shape, since an unmatched selector is a reported trap rather than a
  swallowed key — and the two kinds the second document added in v3.10.0 were
  not listed, so opening a file or cycling documents from under an open menu
  exited with case: no label matches the selector.
• A test case is run in a directory of its own, not the one the harness
  was invoked from (ADR-0406). Every case shared the invoker's, so the one
  case that names a file relatively raced its own concurrent copy — eight
  failures in twenty concurrent pairs, and none after. Only the two harnesses
  that start the program under test changed; a toolchain still runs where it
  was invoked.