Implement the remaining valid spec tests.

And lots of other miscellaneous changes. Rename InstanceWorld to
InstancePlus and reorganize its contents. This still isn't a great name,
but at least now it has a clear purpose.

lib/environ/src/module_environ.rs

@@ -1,12 +1,13 @@
 use cranelift_codegen::ir;
 use cranelift_codegen::ir::{AbiParam, ArgumentPurpose};
 use cranelift_codegen::isa;
+use cranelift_entity::PrimaryMap;
 use cranelift_wasm::{
-    self, translate_module, FuncIndex, Global, GlobalIndex, Memory, MemoryIndex, SignatureIndex,
-    Table, TableIndex, WasmResult,
+    self, translate_module, DefinedFuncIndex, FuncIndex, Global, GlobalIndex, Memory, MemoryIndex,
+    SignatureIndex, Table, TableIndex, WasmResult,
 };
 use func_environ::FuncEnvironment;
-use module::{DataInitializer, Export, LazyContents, MemoryPlan, Module, TableElements, TablePlan};
+use module::{Export, MemoryPlan, Module, TableElements, TablePlan};
 use std::clone::Clone;
 use std::string::String;
 use std::vec::Vec;
@@ -259,3 +260,34 @@ pub fn translate_signature(mut sig: ir::Signature, pointer_type: ir::Type) -> ir
         .push(AbiParam::special(pointer_type, ArgumentPurpose::VMContext));
     sig
 }
+
+/// A data initializer for linear memory.
+pub struct DataInitializer<'data> {
+    /// The index of the memory to initialize.
+    pub memory_index: MemoryIndex,
+    /// Optionally a globalvar base to initialize at.
+    pub base: Option<GlobalIndex>,
+    /// A constant offset to initialize at.
+    pub offset: usize,
+    /// The initialization data.
+    pub data: &'data [u8],
+}
+
+/// References to the input wasm data buffer to be decoded and processed later,
+/// separately from the main module translation.
+pub struct LazyContents<'data> {
+    /// References to the function bodies.
+    pub function_body_inputs: PrimaryMap<DefinedFuncIndex, &'data [u8]>,
+
+    /// References to the data initializers.
+    pub data_initializers: Vec<DataInitializer<'data>>,
+}
+
+impl<'data> LazyContents<'data> {
+    pub fn new() -> Self {
+        Self {
+            function_body_inputs: PrimaryMap::new(),
+            data_initializers: Vec::new(),
+        }
+    }
+}