Fuchsia: Use low-level prng call, add test, update test runner.

runtime/bin/run_vm_tests_fuchsia.cc

Index: runtime/bin/run_vm_tests_fuchsia.cc
diff --git a/runtime/bin/run_vm_tests_fuchsia.cc b/runtime/bin/run_vm_tests_fuchsia.cc
index 431b162777805146524d8bbd81b93ae669d6ee40..2920052af179cbd2f760347a5fd0429db88d132d 100644
--- a/runtime/bin/run_vm_tests_fuchsia.cc
+++ b/runtime/bin/run_vm_tests_fuchsia.cc
@@ -21,8 +21,12 @@
 // command line argument which is the path to a file containing a list of tests
 // to run, one per line.
 
+// TODO(zra): Make this a command line argument
 const char* kRunVmTestsPath = "/boot/bin/dart_vm_tests";
 
+// The simulator only has 512MB;
+const intptr_t kOldGenHeapSizeMB = 256;
+
 // Tests that are invalid, wedge, or cause panics.
 const char* kSkip[] = {
   // These expect a file to exist that we aren't putting in the image.
@@ -63,6 +67,8 @@ const char* kSkip[] = {
   // No realpath.
   "Dart2JSCompilerStats",
   "Dart2JSCompileAll",
+  // Uses too much memory.
+  "PrintJSON",
 };
 
 // Expected to fail/crash.
@@ -139,10 +145,16 @@ static bool isBug(const char* test) {
 
 
 static int run_test(const char* test_name) {
-  const intptr_t kArgc = 2;
-  const char* argv[3];
+  const intptr_t kArgc = 3;
+  const char* argv[kArgc];
+
+  char old_gen_arg[64];
+  snprintf(old_gen_arg, sizeof(old_gen_arg), "--old_gen_heap_size=%ld",
+      kOldGenHeapSizeMB);
+
   argv[0] = kRunVmTestsPath;
-  argv[1] = test_name;
+  argv[1] = old_gen_arg;
+  argv[2] = test_name;
 
   mx_handle_t p = launchpad_launch(argv[0], kArgc, argv);
   if (p < 0) {