fix(test): correctly scrub coq and coq/theories (#10657)

In `[^\s\f]*`, the `\` is interpreted literally, matching a backslash
character. Instead we use `[:space:]` which corresponds to `\s`, but
works in a `[]` context.

In addition, we have to fix the pattern so that it only matches
directories that end with `coq` or `coq/theories`, otherwise it replaces
too many directories and `$TESTCASE_ROOT` gets eaten.

This has the nice benefit of making the coq test suite work under nix,
where `coq/theories` is installed elsewhere.

Signed-off-by: Etienne Millon <me@emillon.org>

test/blackbox-tests/test-cases/coq/compose-installed-compat.t/run.t

@@ -57,7 +57,7 @@ Now we check the flags that were passed to coqdep and coqc:
   $ tail -4 A/_build/log | head -2 | ../scrub_coq_args.sh
   coqdep
   -boot
-  -R $TESTCASE_ROOT/lib/coq/theories Coq
+  -R coq/theories Coq
   -Q $TESTCASE_ROOT/lib/coq/user-contrib/B B
   -R . A -dyndep opt -vos a.v >
   _build/default/.A.theory.d
@@ -67,7 +67,7 @@ Now we check the flags that were passed to coqdep and coqc:
   -nI lib/coq-core/kernel
   -nI .
   -boot
-  -R $TESTCASE_ROOT/lib/coq/theories Coq
+  -R coq/theories Coq
   -Q $TESTCASE_ROOT/lib/coq/user-contrib/B B
   -R . A
   a.v

test/blackbox-tests/test-cases/coq/scrub_coq_args.sh

@@ -17,7 +17,8 @@ sed 's/ -Q/\f-Q/g' | # new line for each -Q
 sed 's/ -w/\f-w/g' | # new line for each -w
 sed 's/ -boot/\f-boot/g' | # new line for each -boot
 sed 's/ -native-compiler /\f-native-compiler /g' | # new line for each -native-compiler
-sed 's/-R [^\s\f]*coq/-R coq/g' | # scrub -R with coq
+sed 's/-R [^[:space:]]*coq /-R coq /g' | # scrub -R with coq
+sed 's#-R [^[:space:]]*coq/theories #-R coq/theories #g' | # scrub -R with coq/theories
 sed 's/-I [-A-Za-z0-9\/_\.]*lib\//-I lib\//g' | # scrub -I with lib/
 sed 's/-nI [-A-Za-z0-9\/_\.]*lib\//-nI lib\//g' | # scrub -nI with lib/
 sed 's/\(-R [^\f]* [^\f]*\) \(.*\)/\1\f\2/g' | # new line after each -R