[test][Dexter] Fix test failure if space in python path

[jhenderson]

Summary

The '%dexter_regression_test' substitution was missing quotes around the python executable, unlike other substitutions of a similar nature in the file. This changes fixes the issue.

[jmorse]

From the file history, this has happened a few times before :(. Ship it.

[jhenderson]

In D96420#2554095, @jmorse wrote:

From the file history, this has happened a few times before :(. Ship it.

I'm not convinced we don't need some kind of general purpose lit solution that solves this, but that's a bigger task than I'm willing to take a stab at currently!

[aganea]

LGTM.

For the record this fixes the issue below on Windows:

******************** TEST 'debuginfo-tests :: dexter/feature_tests/commands/penalty/unreachable.cpp' FAILED ********************
Script:
--
: 'RUN: at line 8';   not C:/Program Files/Python39/python.exe F:/aganea/llvm-project/debuginfo-tests\dexter\dexter.py test --fail-lt 1.0 -w --builder clang-cl_vs2015 --debugger dbgeng --cflags "/Zi /Od" --ldflags "/Zi" -- F:\aganea\llvm-project\debuginfo-tests\dexter\feature_tests\commands\penalty\unreachable.cpp | f:\aganea\llvm-project\buildtest\bin\filecheck.exe F:\aganea\llvm-project\debuginfo-tests\dexter\feature_tests\commands\penalty\unreachable.cpp
--
Exit Code: 2

Command Output (stdout):
--
$ ":" "RUN: at line 8"
$ "not" "C:/Program" "Files/Python39/python.exe" "F:/aganea/llvm-project/debuginfo-tests\dexter\dexter.py" "test" "--fail-lt" "1.0" "-w" "--builder" "clang-cl_vs2015" "--debugger" "dbgeng" "--cflags" "/Zi /Od" "--ldflags" "/Zi" "--" "F:\aganea\llvm-project\debuginfo-tests\dexter\feature_tests\commands\penalty\unreachable.cpp"
# command stderr:
error: program not executable

Python happens to be installed as "available to all users" on this machine, so it was installed on "C:\Program Files" (which before was missing quotes at the right place).

debuginfo-tests/lit.cfg.py

else:
   dexter_regression_test_debugger = "--debugger lldb"
   dexter_regression_test_cflags = '--cflags "-O0 -glldb"'
   dexter_regression_test_ldflags = ''
 
 # Typical command would take the form:
 # ./path_to_py/python.exe ./path_to_dex/dexter.py test --fail-lt 1.0 -w --builder clang --debugger lldb --cflags '-O0 -g'
 dexter_regression_test_command = ' '.join(
   # "python3", "dexter.py", test, fail_mode, builder, debugger, cflags, ldflags
-  ["{}".format(config.python3_executable),
-  "{}".format(dexter_path),
+  ['"{}"'.format(config.python3_executable),
+  '"{}"'.format(dexter_path),
   'test',
   '--fail-lt 1.0 -w',
   dexter_regression_test_builder,
   dexter_regression_test_debugger,
   dexter_regression_test_cflags,
   dexter_regression_test_ldflags])
 
 tools.append(ToolSubst('%dexter_regression_test', dexter_regression_test_command))