It turns out that 'with-continuation-barrier' allows delimited
continuations (i.e., prompts) to get through.
* gash/shell.scm (%subshell): Replace 'with-continuation-barrier' with
'dynamic-wind', making sure to preserve exit statuses that were leaked
through before.
* tests/unit/shell.scm (call-with-temporary-directory): Replace
'with-continuation-barrier' with 'dynamic-wind'.
* tests/spec/oil.scm: Enable previously failing tests.
* configure.ac (GUILE_PKG): Add 2.0.
* gash/textual-ports.scm: New file.
* Makefile.am: Add it.
* gash/lexer.scm, gash/parser.scm, gash/shell.scm: Use it in place of
'(ice-9 textual-ports)'.
* tests/unit/shell.scm: Use it in place of '(ice-9 textual-ports)';
replace '(ice-9 textual-ports)' with '(rnrs io ports)' in sub-scripts;
and add a shim for 'setvbuf'.
This was only relevant to an older implementation of redirects, and
does not make much sense for us now.
* tests/unit/shell.scm (Redirects here-document to standard input):
Remove call to 'setvbuf'.
gash/environment.scm: Remove file.
geesh/*: Move these files into the 'gash' folder and replace all
instances of the word 'geesh'.
scripts/geesh.in: Remove file.
HACKING, INSTALL, Makefile.am, configure.ac, guix.scm,
tests/bootstrap/bash-without-bash.scm, tests/spec/Makefile.am,
tests/spec/check-spec, tests/spec/oil.scm, tests/unit/*,
tools/coverage.in: Replace all instances of the word 'geesh'.
Co-authored-by: Jan Nieuwenhuizen <janneke@gnu.org>