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outdated comment was also fixed.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/isa/x86/binemit.rs

@@ -4,7 +4,7 @@ use super::enc_tables::{needs_offset, needs_sib_byte};
 use super::registers::RU;
 use crate::binemit::{bad_encoding, CodeSink, Reloc};
 use crate::ir::condcodes::{CondCode, FloatCC, IntCC};
-use crate::ir::{Constant, Ebb, Function, Inst, InstructionData, JumpTable, Opcode, TrapCode};
+use crate::ir::{Block, Constant, Function, Inst, InstructionData, JumpTable, Opcode, TrapCode};
 use crate::isa::{RegUnit, StackBase, StackBaseMask, StackRef, TargetIsa};
 use crate::regalloc::RegDiversions;
 
@@ -369,13 +369,13 @@ fn fcc2opc(cond: FloatCC) -> u16 {
 }
 
 /// Emit a single-byte branch displacement to `destination`.
-fn disp1<CS: CodeSink + ?Sized>(destination: Ebb, func: &Function, sink: &mut CS) {
+fn disp1<CS: CodeSink + ?Sized>(destination: Block, func: &Function, sink: &mut CS) {
     let delta = func.offsets[destination].wrapping_sub(sink.offset() + 1);
     sink.put1(delta as u8);
 }
 
 /// Emit a four-byte branch displacement to `destination`.
-fn disp4<CS: CodeSink + ?Sized>(destination: Ebb, func: &Function, sink: &mut CS) {
+fn disp4<CS: CodeSink + ?Sized>(destination: Block, func: &Function, sink: &mut CS) {
     let delta = func.offsets[destination].wrapping_sub(sink.offset() + 4);
     sink.put4(delta);
 }