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outdated comment was also fixed.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/print_errors.rs

@@ -2,7 +2,7 @@
 
 use crate::entity::SecondaryMap;
 use crate::ir;
-use crate::ir::entities::{AnyEntity, Ebb, Inst, Value};
+use crate::ir::entities::{AnyEntity, Block, Inst, Value};
 use crate::ir::function::Function;
 use crate::isa::TargetIsa;
 use crate::result::CodegenError;
@@ -47,15 +47,15 @@ pub fn pretty_verifier_error<'a>(
 struct PrettyVerifierError<'a>(Box<dyn FuncWriter + 'a>, &'a mut Vec<VerifierError>);
 
 impl<'a> FuncWriter for PrettyVerifierError<'a> {
-    fn write_ebb_header(
+    fn write_block_header(
         &mut self,
         w: &mut dyn Write,
         func: &Function,
         isa: Option<&dyn TargetIsa>,
-        ebb: Ebb,
+        block: Block,
         indent: usize,
     ) -> fmt::Result {
-        pretty_ebb_header_error(w, func, isa, ebb, indent, &mut *self.0, self.1)
+        pretty_block_header_error(w, func, isa, block, indent, &mut *self.0, self.1)
     }
 
     fn write_instruction(
@@ -81,18 +81,18 @@ impl<'a> FuncWriter for PrettyVerifierError<'a> {
     }
 }
 
-/// Pretty-print a function verifier error for a given EBB.
-fn pretty_ebb_header_error(
+/// Pretty-print a function verifier error for a given block.
+fn pretty_block_header_error(
     w: &mut dyn Write,
     func: &Function,
     isa: Option<&dyn TargetIsa>,
-    cur_ebb: Ebb,
+    cur_block: Block,
     indent: usize,
     func_w: &mut dyn FuncWriter,
     errors: &mut Vec<VerifierError>,
 ) -> fmt::Result {
     let mut s = String::new();
-    func_w.write_ebb_header(&mut s, func, isa, cur_ebb, indent)?;
+    func_w.write_block_header(&mut s, func, isa, cur_block, indent)?;
     write!(w, "{}", s)?;
 
     // TODO: Use drain_filter here when it gets stabilized
@@ -100,7 +100,7 @@ fn pretty_ebb_header_error(
     let mut printed_error = false;
     while i != errors.len() {
         match errors[i].location {
-            ir::entities::AnyEntity::Ebb(ebb) if ebb == cur_ebb => {
+            ir::entities::AnyEntity::Block(block) if block == cur_block => {
                 if !printed_error {
                     print_arrow(w, &s)?;
                     printed_error = true;