testsuite: fix proc unsupported overriding in modules.exp [PR108899]

The overrider of proc unsupported in modules.exp had two problems
reported by Thomas Schwinge, even after Jakub Jelínek's fix:

- it remained in effect while running other dejagnu testsets

- it didn't quote correctly the argument list passed to it, which
  caused test names to be surrounded by curly braces, as in:

UNSUPPORTED: {...}

This patch fixes both issues, obsoleting and reverting Jakub's change,
by dropping the overrider and renaming the saved proc back, and by
using uplevel's argument list splicing.


Co-authored-by: Thomas Schwinge <thomas@codesourcery.com>

for  gcc/testsuite/ChangeLog

	PR testsuite/108899
	* g++.dg/modules/modules.exp (unsupported): Drop renaming.
	Fix quoting.

gcc/testsuite/g++.dg/modules/modules.exp

@@ -319,15 +319,11 @@ cleanup_module_files [find $DEFAULT_REPO *.gcm]
 # so that, after an unsupported result in dg-test, we can skip rather
 # than fail subsequent related tests.
 set module_do {"compile" "P"}
-if { [info procs unsupported] != [list] \
-      && [info procs saved-unsupported] == [list] } {
-    rename unsupported saved-unsupported
-
-    proc unsupported { args } {
-	global module_do
-	lset module_do 1 "N"
-	return [saved-unsupported $args]
-    }
+rename unsupported modules-saved-unsupported
+proc unsupported { args } {
+    global module_do
+    lset module_do 1 "N"
+    return [uplevel 1 modules-saved-unsupported $args]
 }
 
 # not grouped tests, sadly tcl doesn't have negated glob
@@ -412,4 +408,10 @@ foreach src [lsort [find $srcdir/$subdir {*_a.[CHX}]] {
     }
 }
 
+# Restore the original unsupported proc, lest it will affect
+# subsequent test runs, or even fail renaming if we run modules.exp
+# for multiple targets/multilibs/options.
+rename unsupported {}
+rename modules-saved-unsupported unsupported
+
 dg-finish