Improve type selection in fuzzer (#2424)

- Adds `items` function for `FeatureOptions` so we can get a vector of
  eligible types
- Replaces hardcoded enumeration of MVP types with `getConcreteTypes`,
  which also adds v128 type to the list if SIMD is enabled
- Removes `getType()` function; this does not seem to be used anywhere
- Renames `vectorPick` with `pick`
- Use the absolute path for d8 in the fuzzer

1 files changed, 3 insertions, 1 deletions

diff --git a/check.py b/check.py
index 86a857df5..87178db3d 100755
--- a/check.py
+++ b/check.py
@@ -302,7 +302,9 @@ def run_wasm_reduce_tests():
         before = os.stat('a.wasm').st_size
         run_command(WASM_REDUCE + ['a.wasm', '--command=%s b.wasm --fuzz-exec -all' % WASM_OPT[0], '-t', 'b.wasm', '-w', 'c.wasm'])
         after = os.stat('c.wasm').st_size
-        assert after < 0.6 * before, [before, after]
+        # 0.65 is a custom threshold to check if we have shrunk the output
+        # sufficiently
+        assert after < 0.65 * before, [before, after]
 
 
 def run_spec_tests():