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outdated comment was also fixed.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/filetests/src/test_binemit.rs

@@ -73,8 +73,8 @@ impl binemit::CodeSink for TextSink {
         self.offset += 8;
     }
 
-    fn reloc_ebb(&mut self, reloc: binemit::Reloc, ebb_offset: binemit::CodeOffset) {
-        write!(self.text, "{}({}) ", reloc, ebb_offset).unwrap();
+    fn reloc_block(&mut self, reloc: binemit::Reloc, block_offset: binemit::CodeOffset) {
+        write!(self.text, "{}({}) ", reloc, block_offset).unwrap();
     }
 
     fn reloc_external(
@@ -151,9 +151,9 @@ impl SubTest for TestBinEmit {
 
         // Give an encoding to any instruction that doesn't already have one.
         let mut divert = RegDiversions::new();
-        for ebb in func.layout.ebbs() {
+        for block in func.layout.blocks() {
             divert.clear();
-            for inst in func.layout.ebb_insts(ebb) {
+            for inst in func.layout.block_insts(block) {
                 if !func.encodings[inst].is_legal() {
                     // Find an encoding that satisfies both immediate field and register
                     // constraints.
@@ -181,7 +181,7 @@ impl SubTest for TestBinEmit {
             }
         }
 
-        // Relax branches and compute EBB offsets based on the encodings.
+        // Relax branches and compute block offsets based on the encodings.
         let mut cfg = ControlFlowGraph::with_function(&func);
         let mut domtree = DominatorTree::with_function(&func, &cfg);
         let CodeInfo { total_size, .. } =
@@ -218,15 +218,15 @@ impl SubTest for TestBinEmit {
 
         // Now emit all instructions.
         let mut sink = TextSink::new();
-        for ebb in func.layout.ebbs() {
+        for block in func.layout.blocks() {
             divert.clear();
             // Correct header offsets should have been computed by `relax_branches()`.
             assert_eq!(
-                sink.offset, func.offsets[ebb],
+                sink.offset, func.offsets[block],
                 "Inconsistent {} header offset",
-                ebb
+                block
             );
-            for (offset, inst, enc_bytes) in func.inst_offsets(ebb, &encinfo) {
+            for (offset, inst, enc_bytes) in func.inst_offsets(block, &encinfo) {
                 assert_eq!(sink.offset, offset);
                 sink.text.clear();
                 let enc = func.encodings[inst];
@@ -293,8 +293,8 @@ impl SubTest for TestBinEmit {
 
         for (jt, jt_data) in func.jump_tables.iter() {
             let jt_offset = func.jt_offsets[jt];
-            for ebb in jt_data.iter() {
-                let rel_offset: i32 = func.offsets[*ebb] as i32 - jt_offset as i32;
+            for block in jt_data.iter() {
+                let rel_offset: i32 = func.offsets[*block] as i32 - jt_offset as i32;
                 sink.put4(rel_offset as u32)
             }
         }