fix test_gc for o1 and o2

src/library_gc.js

@@ -115,7 +115,7 @@ if (GC_SUPPORT) {
         var freeList = [];
         for (var ptr in GC.sizes) {
           if (!GC.reachable[ptr]) {
-            freeList.push(ptr);
+            freeList.push(parseInt(ptr));
           }
         }
         for (var i = 0; i < freeList.length; i++) {

system/include/gc.h

@@ -13,6 +13,8 @@ void __attribute__((used)) __GC_KEEPALIVE__() {
   static int times = 1;
   void *x = malloc(times);
   free(x);
+  x = calloc(1, times);
+  free(x);
   x = calloc(times, 1);
   free(x);
   times++;

tests/runner.py

@@ -6186,6 +6186,8 @@ def process(filename):
           printf(".\n");
 
           global = 0;
+
+          return 0;
         }
       '''
       self.do_run(src, '''basic test