Add misc doc improvements to runtime-core

lib/runtime-core/src/backend.rs

@@ -76,9 +76,18 @@ impl Default for MemoryBoundCheckMode {
 }
 
 /// Controls which experimental features will be enabled.
+/// Features usually have a corresponding [WebAssembly proposal][wasm-props].
+///
+/// [wasm-props]: https://github.com/WebAssembly/proposals
 #[derive(Debug, Default)]
 pub struct Features {
+    /// Whether support for the [SIMD proposal][simd-prop] is enabled.
+    ///
+    /// [simd-prop]: https://github.com/webassembly/simd
     pub simd: bool,
+    /// Whether support for the [threads proposal][threads-prop] is enabled.
+    ///
+    /// [threads-prop]: https://github.com/webassembly/threads
     pub threads: bool,
 }
 

lib/runtime-core/src/lib.rs

@@ -173,7 +173,7 @@ pub fn validate_and_report_errors_with_features(
     }
 }
 
-/// Creates a new module from the given cache `Artifact` for the specified compiler backend
+/// Creates a new module from the given cache [`Artifact`] for the specified compiler backend
 pub unsafe fn load_cache_with(
     cache: Artifact,
     compiler: &dyn backend::Compiler,

lib/runtime-core/src/vm.rs

@@ -54,11 +54,14 @@ pub struct Ctx {
     /// This is intended to be user-supplied, per-instance
     /// contextual data. There are currently some issue with it,
     /// notably that it cannot be set before running the `start`
-    /// function in a WebAssembly module.
+    /// function in a WebAssembly module. Additionally, the `data`
+    /// field may be taken by another ABI implementation that the user
+    /// wishes to use in addition to their own, such as WASI.  This issue is
+    /// being discussed at [#1111](https://github.com/wasmerio/wasmer/pull/1111).
     ///
-    /// [#219](https://github.com/wasmerio/wasmer/pull/219) fixes that
-    /// issue, as well as allowing the user to have *per-function*
-    /// context, instead of just per-instance.
+    /// Alternatively, per-function data can be used if the function in the
+    /// [`ImportObject`] is a closure.  This cannot duplicate data though,
+    /// so if data may be shared if the [`ImportObject`] is reused.
     pub data: *mut c_void,
 
     /// If there's a function set in this field, it gets called