Add prefix to cctests when listed to make retrieving them more robust

Bug: v8:12802
Change-Id: I4e12edc71ce110f603026f2b9a446af8965f9510
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3598887Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Almothana Athamneh <almuthanna@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80208}

test/cctest/cctest.cc

@@ -336,9 +336,12 @@ i::Handle<i::JSFunction> Optimize(
 }
 
 static void PrintTestList() {
+  int test_num = 0;
   for (const auto& entry : g_cctests.Get()) {
-    printf("%s\n", entry.first.c_str());
+    printf("**>Test: %s\n", entry.first.c_str());
+    test_num++;
   }
+  printf("\nTotal number of tests: %d\n", test_num);
 }
 
 int main(int argc, char* argv[]) {

test/cctest/testcfg.py

@@ -56,10 +56,20 @@ class TestLoader(testsuite.TestLoader):
       print(output.stderr)
       return []
 
-    filtered_output = [
-        test for test in output.stdout.strip().split()
-        if test.startswith('test-')
-    ]
+    filtered_output = []
+    test_prefix = '**>Test: '
+    test_total_prefix = 'Total number of tests: '
+    tests_total = 0
+
+    for line in output.stdout.strip().splitlines():
+      if line.startswith(test_prefix):
+        filtered_output.append(line[len(test_prefix):])
+      if line.startswith(test_total_prefix):
+        tests_total = int(line[len(test_total_prefix):])
+
+    assert (len(filtered_output) > 0)
+    assert (len(filtered_output) == tests_total)
+
     return sorted(filtered_output)