Say "IR" instead of "IL".

While the specifics of these terms are debatable, "IR" generally
isn't incorrect in this context, and is the more widely recognized
term at this time.

See also the discussion in #267.

Fixes #267.

lib/frontend/src/frontend.rs

@@ -1,4 +1,4 @@
-//! A frontend for building Cretonne IL from other languages.
+//! A frontend for building Cretonne IR from other languages.
 use cretonne::cursor::{Cursor, FuncCursor};
 use cretonne::ir;
 use cretonne::ir::{Ebb, Type, Value, Function, Inst, JumpTable, StackSlot, JumpTableData,
@@ -10,7 +10,7 @@ use ssa::{SSABuilder, SideEffects, Block};
 use cretonne::entity::{EntityRef, EntityMap, EntitySet};
 use cretonne::packed_option::PackedOption;
 
-/// Structure used for translating a series of functions into Cretonne IL.
+/// Structure used for translating a series of functions into Cretonne IR.
 ///
 /// In order to reduce memory reallocations when compiling multiple functions,
 /// `FunctionBuilderContext` holds various data structures which are cleared between
@@ -29,7 +29,7 @@ where
 }
 
 
-/// Temporary object used to build a single Cretonne IL `Function`.
+/// Temporary object used to build a single Cretonne IR `Function`.
 pub struct FunctionBuilder<'a, Variable: 'a>
 where
     Variable: EntityRef,
@@ -103,7 +103,7 @@ where
 }
 
 /// Implementation of the [`InstBuilder`](../cretonne/ir/builder/trait.InstBuilder.html) that has
-/// one convenience method per Cretonne IL instruction.
+/// one convenience method per Cretonne IR instruction.
 pub struct FuncInstBuilder<'short, 'long: 'short, Variable: 'long>
 where
     Variable: EntityRef,
@@ -191,7 +191,7 @@ impl<'short, 'long, Variable> InstBuilderBase<'short> for FuncInstBuilder<'short
     }
 }
 
-/// This module allows you to create a function in Cretonne IL in a straightforward way, hiding
+/// This module allows you to create a function in Cretonne IR in a straightforward way, hiding
 /// all the complexity of its internal representation.
 ///
 /// The module is parametrized by one type which is the representation of variables in your
@@ -203,10 +203,10 @@ impl<'short, 'long, Variable> InstBuilderBase<'short> for FuncInstBuilder<'short
 /// - the last instruction of each block is a terminator instruction which has no natural successor,
 ///   and those instructions can only appear at the end of extended blocks.
 ///
-/// The parameters of Cretonne IL instructions are Cretonne IL values, which can only be created
-/// as results of other Cretonne IL instructions. To be able to create variables redefined multiple
+/// The parameters of Cretonne IR instructions are Cretonne IR values, which can only be created
+/// as results of other Cretonne IR instructions. To be able to create variables redefined multiple
 /// times in your program, use the `def_var` and `use_var` command, that will maintain the
-/// correspondence between your variables and Cretonne IL SSA values.
+/// correspondence between your variables and Cretonne IR SSA values.
 ///
 /// The first block for which you call `switch_to_block` will be assumed to be the beginning of
 /// the function.
@@ -220,7 +220,7 @@ impl<'short, 'long, Variable> InstBuilderBase<'short> for FuncInstBuilder<'short
 ///
 /// # Errors
 ///
-/// The functions below will panic in debug mode whenever you try to modify the Cretonne IL
+/// The functions below will panic in debug mode whenever you try to modify the Cretonne IR
 /// function in a way that violate the coherence of the code. For instance: switching to a new
 /// `Ebb` when you haven't filled the current one with a terminator instruction, inserting a
 /// return instruction with arguments that don't match the function's signature.
@@ -311,7 +311,7 @@ where
         self.func_ctx.types[var] = ty;
     }
 
-    /// Returns the Cretonne IL value corresponding to the utilization at the current program
+    /// Returns the Cretonne IR value corresponding to the utilization at the current program
     /// position of a previously defined user variable.
     pub fn use_var(&mut self, var: Variable) -> Value {
         let ty = *self.func_ctx.types.get(var).expect(
@@ -462,8 +462,8 @@ where
 }
 
 /// All the functions documented in the previous block are write-only and help you build a valid
-/// Cretonne IL functions via multiple debug asserts. However, you might need to improve the
-/// performance of your translation perform more complex transformations to your Cretonne IL
+/// Cretonne IR functions via multiple debug asserts. However, you might need to improve the
+/// performance of your translation perform more complex transformations to your Cretonne IR
 /// function. The functions below help you inspect the function you're creating and modify it
 /// in ways that can be unsafe if used incorrectly.
 impl<'a, Variable> FunctionBuilder<'a, Variable>