Closes #291.

* commit '2f18ba':
  'main': use zsh/parameter to resolve alias
  driver: load zsh/parameter if available

If possible, use zsh/parameter to avoid forks.

Fixes #263.

* upstream/pr/308:
  'main': Fix issue #302, "Process substitution misparsed as redirection".
  'main': Factor out common code.  No functional change.
  'main': Add a regression test for issue #302, "Process substitution misparsed as redirection".

Follow-up to 2176692704.

Part of #306.

Found-by: m0viefreak
(in #298)

* upstream/pr/315:
  'main': optimization that in my tests shows 2.7s -> 2.2s

Consider indexing long buffers (say 300 chars). E.g. following line:
      integer offset=${${buf[start_pos+1,len]}[(i)$needle]}
will gradually go into large indices for first index [a,] and be kept
at large index for second index [,b]. Instead, we can remove already
processed characters from buf:
    proc_buf="${proc_buf[offset + $#arg + 1,-1]}"
$offset and $#arg are small, first index will not be large. $proc_buf
will be smaller and smaller and the second index [,-1] will run shorter
and shorter.

Keep references in prose as '~/.zshrc': using $ZDOTDIR in that context would
be confusing, and people who set $ZDOTDIR understand these references.

This also removes an implicit assumption that ~/.zshrc is idempotent.

Inspired by #312.

Use correct indexing also for cursor-matchingbracket.

Fixup for 95d82568d8

Part of #306

ISEARCH_ACTIVE was renamed ISEARCHMATCH_ACTIVE in workers/38921
(commit f06be0ffcf2c to zsh itself).

Fixes #299.

Closes #297.

Use 'print -r --' instead, so literal backslashes in $BUFFER aren't expanded.

Found-by: Matthew Martin

The new output improves readability of the 'main' highlighter's test output.

Without this when bracket_color_size is 0,
    $(( (levelpos[$pos] - 1) % bracket_color_size + 1 ))
errors with division by zero.

Since the _zsh_highlight_add_highlight that the tests use ignores
ZSH_HIGHLIGHT_STYLES, we can test both an injective mapping and an empty
mapping at once.

Closes #287. Testing the keys directly removes the need for
unused_highlight which will be removed next.

This removes the need for the typepos array.

zsh arrays start at one, and this will make the next commit easier.

Review-by: Matthew Martin

'none' is a valid highlighting type. Since by convention styles are all
lowercase, 'NONE' shouldn't conflict with anything.

Closes #289.