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outdated comment was also fixed.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/filetests/cfg/loop.clif

@@ -5,33 +5,33 @@ test verifier
 function %nonsense(i32, i32) -> f32 {
 ; regex: I=\binst\d+\b
 ; check: digraph "%nonsense" {
-; check:     ebb0 [shape=record, label="{ebb0(v1: i32, v2: i32):
-; check: | <$(BRZ=$I)>brz v2, ebb2
-; nextln: | <$(JUMP0=$I)>jump ebb3
+; check:     block0 [shape=record, label="{block0(v1: i32, v2: i32):
+; check: | <$(BRZ=$I)>brz v2, block2
+; nextln: | <$(JUMP0=$I)>jump block3
 ; nextln: }"]
-; nextln:     ebb3 [shape=record, label="{ebb3:
-; check: | <$(JUMP3=$I)>jump ebb1(v4)
+; nextln:     block3 [shape=record, label="{block3:
+; check: | <$(JUMP3=$I)>jump block1(v4)
 ; nextln: }"]
-; nextln:     ebb1 [shape=record, label="{ebb1(v5: i32):
-; check:  | <$(BRNZ1=$I)>brnz v13, ebb1(v12)
-; nextln: | <$(JUMP1=$I)>jump ebb4
+; nextln:     block1 [shape=record, label="{block1(v5: i32):
+; check:  | <$(BRNZ1=$I)>brnz v13, block1(v12)
+; nextln: | <$(JUMP1=$I)>jump block4
 ; nextln: }"]
-; nextln:    ebb4 [shape=record, label="{ebb4:
+; nextln:    block4 [shape=record, label="{block4:
 ; check:  | <$I>return v17
 ; nextln: }"]
-; nextln:    ebb2 [shape=record, label="{ebb2:
+; nextln:    block2 [shape=record, label="{block2:
 ; check:  | <$I>return v100
 ; check:}"]
-ebb0(v1: i32, v2: i32):
+block0(v1: i32, v2: i32):
     v3 = f64const 0x0.0
-    brz v2, ebb2            ; unordered: ebb0:$BRZ -> ebb2
-    jump ebb3               ; unordered: ebb0:$JUMP0 -> ebb3
+    brz v2, block2            ; unordered: block0:$BRZ -> block2
+    jump block3               ; unordered: block0:$JUMP0 -> block3
 
-ebb3:
+block3:
     v4 = iconst.i32 0
-    jump ebb1(v4)           ; unordered: ebb3:$JUMP3 -> ebb1
+    jump block1(v4)           ; unordered: block3:$JUMP3 -> block1
 
-ebb1(v5: i32):
+block1(v5: i32):
     v6 = imul_imm v5, 4
     v7 = iadd v1, v6
     v8 = f32const 0.0
@@ -40,17 +40,17 @@ ebb1(v5: i32):
     v11 = fadd v9, v10
     v12 = iadd_imm v5, 1
     v13 = icmp ult v12, v2
-    brnz v13, ebb1(v12)     ; unordered: ebb1:$BRNZ1 -> ebb1
-    jump ebb4               ; unordered: ebb1:$JUMP1 -> ebb4
+    brnz v13, block1(v12)     ; unordered: block1:$BRNZ1 -> block1
+    jump block4               ; unordered: block1:$JUMP1 -> block4
 
-ebb4:
+block4:
     v14 = f64const 0.0
     v15 = f64const 0.0
     v16 = fdiv v14, v15
     v17 = f32const 0.0
     return v17
 
-ebb2:
+block2:
     v100 = f32const 0.0
     return v100
 }

cranelift/filetests/filetests/cfg/traps_early.clif

@@ -6,16 +6,16 @@ test verifier
 function %nonsense(i32) {
 ; check: digraph "%nonsense" {
 
-ebb0(v1: i32):
+block0(v1: i32):
     trap user0      ; error: terminator instruction was encountered before the end
-    brnz v1, ebb2   ; unordered: ebb0:inst1 -> ebb2
-    jump ebb1       ; unordered: ebb0:inst2 -> ebb1
+    brnz v1, block2   ; unordered: block0:inst1 -> block2
+    jump block1       ; unordered: block0:inst2 -> block1
 
-ebb1:
+block1:
     v2 = iconst.i32 0
     v3 = iadd v1, v3
-    jump ebb0(v3)   ; unordered: ebb1:inst5 -> ebb0
+    jump block0(v3)   ; unordered: block1:inst5 -> block0
 
-ebb2:
+block2:
     return v1
 }

cranelift/filetests/filetests/cfg/unused_node.clif

@@ -3,25 +3,25 @@ test print-cfg
 
 function %not_reached(i32) -> i32 {
 ; check: digraph "%not_reached" {
-; check:     ebb0 [shape=record, label="{ebb0(v0: i32):
-; check:  | <inst0>brnz v0, ebb2
+; check:     block0 [shape=record, label="{block0(v0: i32):
+; check:  | <inst0>brnz v0, block2
 ; check:  | <inst1>trap user0
 ; check: }"]
-; check:     ebb1 [shape=record, label="{ebb1:
-; check:  | <inst4>jump ebb0(v2)
+; check:     block1 [shape=record, label="{block1:
+; check:  | <inst4>jump block0(v2)
 ; check: }"]
-; check:     ebb2 [shape=record, label="{ebb2:
+; check:     block2 [shape=record, label="{block2:
 ; check:  | <inst5>return v0
 ; check: }"]
-ebb0(v0: i32):
-    brnz v0, ebb2       ; unordered: ebb0:inst0 -> ebb2
+block0(v0: i32):
+    brnz v0, block2       ; unordered: block0:inst0 -> block2
     trap user0
 
-ebb1:
+block1:
     v1 = iconst.i32 1
     v2 = iadd v0, v1
-    jump ebb0(v2)       ; unordered: ebb1:inst4 -> ebb0
+    jump block0(v2)       ; unordered: block1:inst4 -> block0
 
-ebb2:
+block2:
     return v0
 }