Sync wasmparser/wasm-smith on bulk-memory

Historically in bytecodealliance#410 fuzzing for `wasm-tools smith` was updated to
unconditionally enable the bulk-memory proposal if the reference-types
proposal was enabled. This doesn't prevent configuration on the CLI,
however, as exposed in bytecodealliance#1324. This change undoes bytecodealliance#410 effectively and
then syncs the `wasm-smith` crate's understanding of bulk-memory and
reference-types with `wasmparser`'s understanding.

I'm not actually sure if `wasmparser`'s understanding of
bulk-memory-vs-reference-types is correct. It was always a bit murky to
me precisely which instructions where in which proposal, so I've opted
here to take whatever `wasmparser` does today as the source of truth.
Any edits necessary to move items between proposals can be done in
`wasmparser` and then reflected in `wasm-smith`.

crates/wasm-smith/src/config.rs

@@ -576,7 +576,7 @@ impl<'a> Arbitrary<'a> for SwarmConfig {
             max_tables,
             max_memory_pages: u.arbitrary()?,
             min_uleb_size: u.int_in_range(0..=5)?,
-            bulk_memory_enabled: reference_types_enabled || u.arbitrary()?,
+            bulk_memory_enabled: u.arbitrary()?,
             reference_types_enabled,
             simd_enabled: u.arbitrary()?,
             multi_value_enabled: u.arbitrary()?,

crates/wasm-smith/src/core.rs

@@ -1149,11 +1149,13 @@ impl Module {
 
         // Reference types allows us to create passive and declared element
         // segments.
-        if self.config.reference_types_enabled() {
+        if self.config.bulk_memory_enabled() {
             funcrefs.push(Box::new(|_| Ok((ElementKind::Passive, None))));
-            externrefs.push(Box::new(|_| Ok((ElementKind::Passive, None))));
             funcrefs.push(Box::new(|_| Ok((ElementKind::Declared, None))));
-            externrefs.push(Box::new(|_| Ok((ElementKind::Declared, None))));
+            if self.config.reference_types_enabled() {
+                externrefs.push(Box::new(|_| Ok((ElementKind::Passive, None))));
+                externrefs.push(Box::new(|_| Ok((ElementKind::Declared, None))));
+            }
         }
 
         let mut choices = Vec::new();

crates/wasm-smith/src/core/code_builder.rs

@@ -4814,7 +4814,7 @@ fn table_grow(
 
 #[inline]
 fn table_copy_valid(module: &Module, builder: &mut CodeBuilder) -> bool {
-    module.config.reference_types_enabled()
+    module.config.bulk_memory_enabled()
     && !module.config.disallow_traps() // Non-trapping table.copy generation not yet implemented
         && module.tables.len() > 0
         && builder.types_on_stack(&[ValType::I32, ValType::I32, ValType::I32])
@@ -4838,7 +4838,7 @@ fn table_copy(
 
 #[inline]
 fn table_init_valid(module: &Module, builder: &mut CodeBuilder) -> bool {
-    module.config.reference_types_enabled()
+    module.config.bulk_memory_enabled()
     && !module.config.disallow_traps() // Non-trapping table.init generation not yet implemented.
         && builder.allocs.table_init_possible
         && builder.types_on_stack(&[ValType::I32, ValType::I32, ValType::I32])
@@ -4869,7 +4869,7 @@ fn table_init(
 
 #[inline]
 fn elem_drop_valid(module: &Module, _builder: &mut CodeBuilder) -> bool {
-    module.config.reference_types_enabled() && module.elems.len() > 0
+    module.config.bulk_memory_enabled() && module.elems.len() > 0
 }
 
 fn elem_drop(

fuzz/src/validate_valid_module.rs

@@ -29,8 +29,8 @@ pub fn run(u: &mut Unstructured<'_>) -> Result<()> {
         component_model: generate_component,
         multi_value: config.multi_value_enabled,
         multi_memory: config.max_memories > 1,
-        bulk_memory: true,
-        reference_types: true,
+        bulk_memory: config.bulk_memory_enabled,
+        reference_types: config.reference_types_enabled,
         simd: config.simd_enabled,
         relaxed_simd: config.relaxed_simd_enabled,
         memory64: config.memory64_enabled,