shorten loop control flow labels

Author: GYT

llvm/test/Transforms/LoopVectorize/diag-disabled-vectorization-msgs.ll

@@ -85,19 +85,19 @@ exit:
 ; CHECK: LV: Loop hints prevent vectorization
 define void @disable_nonforced(ptr nocapture %a, i32 %n) {
 entry:
-  br label %for.body
+  br label %loop
 
-for.body:
-  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
+loop:
+  %indvars.iv = phi i64 [ %indvars.iv.next, %loop ], [ 0, %entry ]
   %arrayidx = getelementptr inbounds i32, ptr %a, i64 %indvars.iv
   %0 = trunc i64 %indvars.iv to i32
   store i32 %0, ptr %arrayidx, align 4
   %indvars.iv.next = add i64 %indvars.iv, 1
   %lftr.wideiv = trunc i64 %indvars.iv.next to i32
   %exitcond = icmp eq i32 %lftr.wideiv, %n
-  br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !2
+  br i1 %exitcond, label %end, label %loop, !llvm.loop !2
 
-for.end:
+end:
   ret void
 }