Reland emitting of DataCount section (#2027)

This reverts commit cb2d63586c08a3dd194d2b733ceb3f5051c081f8.
The issues with feature validation were mostly resolved in #1993, and
this PR finishes the job by adding feature flags to wasm-as to avoid
emitting the DataCount section when bulk-memory is not enabled.

1 files changed, 15 insertions, 0 deletions

diff --git a/test/unit/test_datacount.py b/test/unit/test_datacount.py
new file mode 100644
index 000000000..5ec98c549
--- /dev/null
+++ b/test/unit/test_datacount.py
@@ -0,0 +1,15 @@
+from scripts.test.shared import WASM_OPT, run_process
+from utils import BinaryenTestCase
+
+
+class DataCountTest(BinaryenTestCase):
+  def test_datacount(self):
+    self.roundtrip('bulkmem_data.wasm')
+
+  def test_bad_datacount(self):
+    path = self.input_path('bulkmem_bad_datacount.wasm')
+    p = run_process(WASM_OPT + ['-g', '-o', '-', path], check=False,
+                    capture_output=True)
+    self.assertNotEqual(p.returncode, 0)
+    self.assertIn('Number of segments does not agree with DataCount section',
+                  p.stderr)