Update '-list' option (#2457)

'-list' option is used to print all sub-tests. But some test do not
support it at all. And all test do not display it the same way, making
it quite complicated for external tools to extract them.

That CL clean the usage so that tests:
- Print the sub-tests list with either '-list' (to prevent breaking
legacy usage) or '--list' (to match other options)
- Do not print anything else when the option is used

test_common/harness/parseParameters.cpp

@@ -35,6 +35,7 @@ std::string gCompilationProgram = DEFAULT_COMPILATION_PROGRAM;
 bool gDisableSPIRVValidation = false;
 std::string gSPIRVValidator = DEFAULT_SPIRV_VALIDATOR;
 unsigned gNumWorkerThreads;
+bool gListTests = false;
 
 void helpInfo()
 {
@@ -49,6 +50,8 @@ void helpInfo()
             spir-v     Use SPIR-V offline compilation
     --num-worker-threads <num>
         Select parallel execution with the specified number of worker threads.
+    --list
+        List sub-tests
 
 For offline compilation (binary and spir-v modes) only:
     --compilation-cache-mode <cache-mode>
@@ -104,6 +107,11 @@ int parseCustomParam(int argc, const char *argv[], const char *ignore)
             // option and print its own help.
             helpInfo();
         }
+        else if (!strcmp(argv[i], "--list") || !strcmp(argv[i], "-list"))
+        {
+            delArg++;
+            gListTests = true;
+        }
         else if (!strcmp(argv[i], "--compilation-mode"))
         {
             delArg++;