Minir typo/Grammar fixes (#6187)

* fix typo

* add test to check that Option<EntityRef> is twice as large as EntityRef

* grammar

* grammar

* reverse snakecase -- Not sure if folks want this type of change

cranelift/codegen/src/ir/dfg.rs

@@ -138,10 +138,10 @@ pub struct DataFlowGraph {
     /// Saves Value labels.
     pub values_labels: Option<BTreeMap<Value, ValueLabelAssignments>>,
 
-    /// Constants used within the function
+    /// Constants used within the function.
     pub constants: ConstantPool,
 
-    /// Stores large immediates that otherwise will not fit on InstructionData
+    /// Stores large immediates that otherwise will not fit on InstructionData.
     pub immediates: PrimaryMap<Immediate, ConstantData>,
 
     /// Jump tables used in this function.
@@ -275,12 +275,12 @@ fn resolve_aliases(values: &PrimaryMap<Value, ValueDataPacked>, value: Value) ->
     }
 }
 
-/// Iterator over all Values in a DFG
+/// Iterator over all Values in a DFG.
 pub struct Values<'a> {
     inner: entity::Iter<'a, Value, ValueDataPacked>,
 }
 
-/// Check for non-values
+/// Check for non-values.
 fn valid_valuedata(data: ValueDataPacked) -> bool {
     let data = ValueData::from(data);
     if let ValueData::Alias {

cranelift/codegen/src/ir/entities.rs

@@ -336,7 +336,7 @@ entity_impl!(UserExternalNameRef, "userextname");
 /// An opaque reference to a function [`Signature`](super::Signature).
 ///
 /// `SigRef`s are used to declare a function with
-/// [`FunctionBuiler::import_function`](https://docs.rs/cranelift-frontend/*/cranelift_frontend/struct.FunctionBuilder.html#method.import_function)
+/// [`FunctionBuilder::import_function`](https://docs.rs/cranelift-frontend/*/cranelift_frontend/struct.FunctionBuilder.html#method.import_function)
 /// as well as to make an [indirect function call](super::InstBuilder::call_indirect).
 ///
 /// `SigRef`s can be created with
@@ -551,6 +551,14 @@ mod tests {
         );
     }
 
+    #[test]
+    fn memory_option() {
+        use core::mem;
+        // PackedOption is used because Option<EntityRef> is twice as large
+        // as EntityRef. If this ever fails to be the case, this test will fail.
+        assert_eq!(mem::size_of::<Value>() * 2, mem::size_of::<Option<Value>>());
+    }
+
     #[test]
     fn constant_with_number() {
         assert_eq!(Constant::with_number(0).unwrap().to_string(), "const0");

cranelift/codegen/src/ir/function.rs

@@ -230,7 +230,7 @@ impl FunctionStencil {
         self.global_values.push(data)
     }
 
-    /// Find the global dyn_scale value associated with given DynamicType
+    /// Find the global dyn_scale value associated with given DynamicType.
     pub fn get_dyn_scale(&self, ty: DynamicType) -> GlobalValue {
         self.dfg.dynamic_types.get(ty).unwrap().dynamic_scale
     }

cranelift/codegen/src/ir/jumptable.rs

@@ -28,7 +28,7 @@ pub struct JumpTableData {
 }
 
 impl JumpTableData {
-    /// Create a new jump table with the provided blocks
+    /// Create a new jump table with the provided blocks.
     pub fn new(def: BlockCall, table: &[BlockCall]) -> Self {
         Self {
             table: std::iter::once(def).chain(table.iter().copied()).collect(),

cranelift/codegen/src/ir/layout.rs

@@ -375,7 +375,7 @@ impl Layout {
 }
 
 /// A single node in the linked-list of blocks.
-// Whenever you add new fields here, don't forget to update the custom serializer for `Layout` too.
+// **Note:** Whenever you add new fields here, don't forget to update the custom serializer for `Layout` too.
 #[derive(Clone, Debug, Default, PartialEq, Hash)]
 struct BlockNode {
     prev: PackedOption<Block>,

cranelift/codegen/src/ir/mod.rs

@@ -89,7 +89,7 @@ pub struct ValueLabelStart {
     pub label: ValueLabel,
 }
 
-/// Value label assignements: label starts or value aliases.
+/// Value label assignments: label starts or value aliases.
 #[derive(Debug, Clone, PartialEq, Hash)]
 #[cfg_attr(feature = "enable-serde", derive(Serialize, Deserialize))]
 pub enum ValueLabelAssignments {