Pass -S to subprocesses in tests

It's bad that we need to do that right now, but it's not the job of
these tests to test that.

src/jit.cpp

@@ -463,7 +463,7 @@ static int main(int argc, char** argv) noexcept {
         // if the user invoked `pyston -c command`
         if (command != NULL) {
             try {
-                main_module = createModule(boxString("__main__"), "<string>");
+                main_module = createModule(autoDecref(boxString("__main__")), "<string>");
                 AST_Module* m = parse_string(command, /* future_flags = */ 0);
                 compileAndRunModule(m, main_module);
                 rtncode = 0;

test/tests/dash_c.py

-# expected: reffail
 import sys
 import subprocess
 
@@ -13,13 +12,13 @@ with open('/dev/null')as ignore:
         print code
         sys.stdout.flush()
 
-    run(["-c", "print 2 + 2"])
-    run(["-c", "import sys; print sys.argv", "hello", "world"])
-    run(["-c", "import sys; print sys.argv", "-c", "this is ignored"])
+    run(["-Sc", "print 2 + 2"])
+    run(["-Sc", "import sys; print sys.argv", "hello", "world"])
+    run(["-Sc", "import sys; print sys.argv", "-c", "this is ignored"])
 
-    run(["-c"])
-    run(["-c", "-c"])
-    run(["-c", "this should not work"])
+    run(["-Sc"])
+    run(["-Sc", "-c"])
+    run(["-Sc", "this should not work"])
 
-    run(["-c", ";"])
-    run(["-cprint 1"])
+    run(["-Sc", ";"])
+    run(["-Scprint 1"])

test/tests/dash_m.py

@@ -16,9 +16,9 @@ with open('/dev/null')as ignore:
         print p.returncode
 
     # just prints out the usage
-    run(["-m", "pydoc"])
+    run(["-Sm", "pydoc"])
 
-    run(["-m", "doesnt_exist"])
+    run(["-Sm", "doesnt_exist"])
 
     os.environ["PYTHONPATH"] = os.path.dirname(__file__)
-    run(["-m", "import_target"])
+    run(["-Sm", "import_target"])

test/tests/native_print_tb.py

-# expected: reffail
 import sys
 import subprocess
 
 me = sys.executable
 
-p = subprocess.Popen([me, "-c", "1/0"], stdout=subprocess.PIPE)
+p = subprocess.Popen([me, "-Sc", "1/0"], stdout=subprocess.PIPE)
 
 print p.stdout.read()