Remove module_start from ArtifactBuild::new, provide builder instead

Remove the added module_start argument in ArtifactBuild::new() to avoid
a breaking change.

Introduce a with_module_start() method instead.

lib/compiler/src/artifact_builders/artifact_builder.rs

@@ -43,7 +43,6 @@ impl ArtifactBuild {
         target: &Target,
         memory_styles: PrimaryMap<MemoryIndex, MemoryStyle>,
         table_styles: PrimaryMap<TableIndex, TableStyle>,
-        module_start: Option<Pages>,
     ) -> Result<Self, CompileError> {
         let environ = ModuleEnvironment::new();
         let features = inner_engine.features().clone();
@@ -120,11 +119,17 @@ impl ArtifactBuild {
             compile_info,
             data_initializers,
             cpu_features: cpu_features.as_u64(),
-            module_start,
+            module_start: None,
         };
         Ok(Self { serializable })
     }
 
+    /// Specify the fixed virtual memory address for the compiled module
+    pub fn with_module_start(mut self, module_start: Option<Pages>) -> Self {
+        self.serializable.module_start = module_start;
+        self
+    }
+
     /// Compile a data buffer into a `ArtifactBuild`, which may then be instantiated.
     #[cfg(not(feature = "compiler"))]
     #[cfg(not(target_arch = "wasm32"))]

lib/compiler/src/engine/artifact.rs

@@ -83,8 +83,8 @@ impl Artifact {
             engine.target(),
             memory_styles,
             table_styles,
-            tunables.module_start(),
-        )?;
+        )?
+        .with_module_start(tunables.module_start());
 
         Self::from_parts(&mut inner_engine, artifact)
     }