JavaScript Backend: fix "improper shell usage errors" in testsuite

Description

The JS backend produces a lot of failures in the testsuite that look like:

Wrong exit code for T10955dyn()(expected 0 , actual 2 )
Stderr ( T10955dyn ):
--- /dev/null	2022-10-10 09:23:06.946692095 +0200
+++ "/tmp/ghctest-64akgqpm/test   spaces/testsuite/tests/haddock/perf/haddock_parser_perf.run/haddock_parser_perf.run.stderr.normalised"	2022-10-11 21:43:49.522168985 +0200
@@ -0,0 +1,2 @@
+egrep: warning: egrep is obsolescent; using grep -E
+egrep: warning: egrep is obsolescent; using grep -E
--- /dev/null	2022-10-10 09:23:06.946692095 +0200
+++ "/tmp/ghctest-64akgqpm/test   spaces/testsuite/tests/haddock/perf/haddock_renamer_perf.run/haddock_renamer_perf.run.stderr.normalised"	2022-10-11 21:43:49.885502306 +0200
@@ -0,0 +1,2 @@
+egrep: warning: egrep is obsolescent; using grep -E
+egrep: warning: egrep is obsolescent; using grep -E

Should be an easy fix.

Impacted Tests

• cabal01
• cabal03
• cabal04
• cabal05
• cabal06
• cabal08
• cabal09
• cabal10
• bkpcabal01
• bkpcabal02
• bkpcabal03
• bkpcabal04
• bkpcabal05
• bkpcabal06
• bkpcabal07

added javascript testsuite labels

assigned to @doyougnu, @hsyl20, @JoshMeredith, and @luite

Related MR: !9133 (merged)

changed the description

mentioned in commit doyougnu/ghc@e042923a

mentioned in commit 73f423c6

added Ttask label

mentioned in commit 3f9ec9ae

mentioned in merge request !10308 (closed)

mentioned in commit f2f06987

mentioned in commit ab6c1d29

Fixed by !10308 (closed)

closed

mentioned in commit da6a1706

mentioned in merge request !10428 (closed)