Mass rename Ebb and relatives to Block (#1365)

* Manually rename BasicBlock to BlockPredecessor

BasicBlock is a pair of (Ebb, Inst) that is used to represent the
basic block subcomponent of an Ebb that is a predecessor to an Ebb.

Eventually we will be able to remove this struct, but for now it
makes sense to give it a non-conflicting name so that we can start
to transition Ebb to represent a basic block.

I have not updated any comments that refer to BasicBlock, as
eventually we will remove BlockPredecessor and replace with Block,
which is a basic block, so the comments will become correct.

* Manually rename SSABuilder block types to avoid conflict

SSABuilder has its own Block and BlockData types. These along with
associated identifier will cause conflicts in a later commit, so
they are renamed to be more verbose here.

* Automatically rename 'Ebb' to 'Block' in *.rs

* Automatically rename 'EBB' to 'block' in *.rs

* Automatically rename 'ebb' to 'block' in *.rs

* Automatically rename 'extended basic block' to 'basic block' in *.rs

* Automatically rename 'an basic block' to 'a basic block' in *.rs

* Manually update comment for `Block`

`Block`'s wikipedia article required an update.

* Automatically rename 'an `Block`' to 'a `Block`' in *.rs

* Automatically rename 'extended_basic_block' to 'basic_block' in *.rs

* Automatically rename 'ebb' to 'block' in *.clif

* Manually rename clif constant that contains 'ebb' as substring to avoid conflict

* Automatically rename filecheck uses of 'EBB' to 'BB'

'regex: EBB' -> 'regex: BB'
'$EBB' -> '$BB'

* Automatically rename 'EBB' 'Ebb' to 'block' in *.clif

* Automatically rename 'an block' to 'a block' in *.clif

* Fix broken testcase when function name length increases

Test function names are limited to 16 characters. This causes
the new longer name to be truncated and fail a filecheck test. An
outdated comment was also fixed.

cranelift/codegen/src/ir/entities.rs

@@ -1,7 +1,7 @@
 //! Cranelift IR entity references.
 //!
 //! Instructions in Cranelift IR need to reference other entities in the function. This can be other
-//! parts of the function like extended basic blocks or stack slots, or it can be external entities
+//! parts of the function like basic blocks or stack slots, or it can be external entities
 //! that are declared in the function preamble in the text format.
 //!
 //! These entity references in instruction operands are not implemented as Rust references both
@@ -25,20 +25,19 @@ use core::u32;
 #[cfg(feature = "enable-serde")]
 use serde::{Deserialize, Serialize};
 
-/// An opaque reference to an [extended basic
-/// block](https://en.wikipedia.org/wiki/Extended_basic_block) in a
+/// An opaque reference to a [basic block](https://en.wikipedia.org/wiki/Basic_block) in a
 /// [`Function`](super::function::Function).
 ///
-/// You can get an `Ebb` using
-/// [`FunctionBuilder::create_ebb`](https://docs.rs/cranelift-frontend/*/cranelift_frontend/struct.FunctionBuilder.html#method.create_ebb)
+/// You can get a `Block` using
+/// [`FunctionBuilder::create_block`](https://docs.rs/cranelift-frontend/*/cranelift_frontend/struct.FunctionBuilder.html#method.create_block)
 ///
 /// While the order is stable, it is arbitrary and does not necessarily resemble the layout order.
 #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-pub struct Ebb(u32);
-entity_impl!(Ebb, "ebb");
+pub struct Block(u32);
+entity_impl!(Block, "block");
 
-impl Ebb {
-    /// Create a new EBB reference from its number. This corresponds to the `ebbNN` representation.
+impl Block {
+    /// Create a new block reference from its number. This corresponds to the `blockNN` representation.
     ///
     /// This method is for use by the parser.
     pub fn with_number(n: u32) -> Option<Self> {
@@ -371,8 +370,8 @@ impl Table {
 pub enum AnyEntity {
     /// The whole function.
     Function,
-    /// An extended basic block.
-    Ebb(Ebb),
+    /// a basic block.
+    Block(Block),
     /// An instruction.
     Inst(Inst),
     /// An SSA value.
@@ -397,7 +396,7 @@ impl fmt::Display for AnyEntity {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             Self::Function => write!(f, "function"),
-            Self::Ebb(r) => r.fmt(f),
+            Self::Block(r) => r.fmt(f),
             Self::Inst(r) => r.fmt(f),
             Self::Value(r) => r.fmt(f),
             Self::StackSlot(r) => r.fmt(f),
@@ -417,9 +416,9 @@ impl fmt::Debug for AnyEntity {
     }
 }
 
-impl From<Ebb> for AnyEntity {
-    fn from(r: Ebb) -> Self {
-        Self::Ebb(r)
+impl From<Block> for AnyEntity {
+    fn from(r: Block) -> Self {
+        Self::Block(r)
     }
 }