[llvm-dwarfdump][Statistics] Change the coverage buckets representation. NFC

Summary:
This changes the representation of 'coverage buckets' in llvm-dwarfdump and
llvm-locstats to one that makes more clear what the buckets contain.

See some related details in D71070.

Reviewers: djtodoro, aprantl, cmtice, jhenderson

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71366
diff --git a/llvm/utils/llvm-locstats/llvm-locstats.py b/llvm/utils/llvm-locstats/llvm-locstats.py
index 408513c..2bbc3f1 100755
--- a/llvm/utils/llvm-locstats/llvm-locstats.py
+++ b/llvm/utils/llvm-locstats/llvm-locstats.py
@@ -15,9 +15,9 @@
 
 def coverage_buckets():
   yield '0%'
-  yield '1-9%'
+  yield '[1%,10%)'
   for start in range(10, 91, 10):
-    yield '{0}-{1}%'.format(start, start + 9)
+    yield '[{0}%,{1}%)'.format(start, start + 10)
   yield '100%'
 
 def locstats_output(
@@ -44,10 +44,10 @@
   print (' =================================================')
   print ('            Debug Location Statistics       ')
   print (' =================================================')
-  print ('     cov%          samples          percentage(~)  ')
+  print ('     cov%           samples         percentage(~)  ')
   print (' -------------------------------------------------')
   for cov_bucket in coverage_buckets():
-    print ('   {0:6}        {1:8d}             {2:3d}%'. \
+    print ('   {0:10}     {1:8d}              {2:3d}%'. \
       format(cov_bucket, variables_coverage_map[cov_bucket], \
              variables_coverage_per_map[cov_bucket]))
   print (' =================================================')