Convert compilation artifacts to just bytes (#3239)

* Convert compilation artifacts to just bytes

This commit strips the `CompilationArtifacts` type down to simply a list
of bytes. This moves all extra metadata elsewhere to live within the
list of bytes itself as `bincode`-encoded information.

Small affordance is made to avoid an in-process
serialize-then-deserialize round-trip for use cases like `Module::new`,
but otherwise this is mostly just moving some data around.

* Rename data section to `.rodata.wasm`

crates/wasmtime/src/engine.rs

@@ -147,6 +147,7 @@ impl Engine {
         #[cfg(feature = "wat")]
         let bytes = wat::parse_bytes(&bytes)?;
         let (_, artifacts, types) = crate::Module::build_artifacts(self, &bytes)?;
+        let artifacts = artifacts.into_iter().map(|i| i.0).collect::<Vec<_>>();
         crate::module::SerializedModule::from_artifacts(self, &artifacts, &types).to_bytes()
     }
 

crates/wasmtime/src/module.rs

@@ -10,7 +10,7 @@ use std::path::Path;
 use std::sync::Arc;
 use wasmparser::Validator;
 use wasmtime_environ::{ModuleEnvironment, ModuleIndex, PrimaryMap};
-use wasmtime_jit::{CompilationArtifacts, CompiledModule, TypeTables};
+use wasmtime_jit::{CompilationArtifacts, CompiledModule, CompiledModuleInfo, TypeTables};
 
 mod registry;
 mod serialization;
@@ -312,8 +312,8 @@ impl Module {
             }
         };
 
-        let modules = engine.run_maybe_parallel(artifacts, |a| {
-            CompiledModule::from_artifacts(a, &*engine.config().profiler)
+        let modules = engine.run_maybe_parallel(artifacts, |(a, i)| {
+            CompiledModule::from_artifacts(a, Some(i), &*engine.config().profiler)
         })?;
 
         Self::from_parts(engine, modules, main_module, Arc::new(types), &[])
@@ -339,7 +339,11 @@ impl Module {
     pub(crate) fn build_artifacts(
         engine: &Engine,
         wasm: &[u8],
-    ) -> Result<(usize, Vec<CompilationArtifacts>, TypeTables)> {
+    ) -> Result<(
+        usize,
+        Vec<(CompilationArtifacts, CompiledModuleInfo)>,
+        TypeTables,
+    )> {
         let tunables = &engine.config().tunables;
 
         // First a `ModuleEnvironment` is created which records type information

crates/wasmtime/src/module/serialization.rs

@@ -246,7 +246,7 @@ impl<'a> SerializedModule<'a> {
         self.check_features(&engine.config().features)?;
 
         let modules = engine.run_maybe_parallel(self.artifacts, |i| {
-            CompiledModule::from_artifacts(i.unwrap_owned(), &*engine.config().profiler)
+            CompiledModule::from_artifacts(i.unwrap_owned(), None, &*engine.config().profiler)
         })?;
 
         assert!(!modules.is_empty());