Revert "[coverage] change block range to avoid ambiguity."

This reverts commit 471fef04.

Reason for revert: A more general fix incoming at https://crrev.com/c/1273095.

Original change's description:
> [coverage] change block range to avoid ambiguity.
> 
> By moving the block range end to left of closing bracket,
> we can avoid ambiguity where an open-ended singleton range
> could be both interpreted as inside the parent range, or
> next to it.
> 
> R=​verwaest@chromium.org
> 
> Bug: v8:8237
> Change-Id: Ibc9412b31efe900b6d8bff0d8fa8c52ddfbf460a
> Reviewed-on: https://chromium-review.googlesource.com/1254127
> Reviewed-by: Georg Neis <neis@chromium.org>
> Commit-Queue: Yang Guo <yangguo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56347}

TBR=yangguo@chromium.org,neis@chromium.org,verwaest@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:8237
Change-Id: I39310cf3c2f06a0d98ff314740aaeefbfffc0834
Reviewed-on: https://chromium-review.googlesource.com/c/1273096Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56513}

src/debug/debug-coverage.cc

@@ -81,11 +81,6 @@ std::vector<CoverageBlock> GetSortedBlockData(SharedFunctionInfo* shared) {
   std::vector<CoverageBlock> result;
   if (coverage_info->SlotCount() == 0) return result;
 
-  if (FLAG_trace_block_coverage) {
-    PrintF("Collecting coverage data\n");
-    coverage_info->Print(shared->DebugName()->ToCString());
-  }
-
   for (int i = 0; i < coverage_info->SlotCount(); i++) {
     const int start_pos = coverage_info->StartSourcePosition(i);
     const int until_pos = coverage_info->EndSourcePosition(i);

src/objects/debug-objects.cc

@@ -375,7 +375,7 @@ void CoverageInfo::Print(std::unique_ptr<char[]> function_name) {
 
   for (int i = 0; i < SlotCount(); i++) {
     os << "{" << StartSourcePosition(i) << "," << EndSourcePosition(i) << "}"
-       << ": " << BlockCount(i) << std::endl;
+       << std::endl;
   }
 }
 

src/parsing/parser-base.h

@@ -5097,7 +5097,6 @@ typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseBlock(
   Expect(Token::LBRACE, CHECK_OK_CUSTOM(NullStatement));
   {
     BlockState block_state(zone(), &scope_);
-    // Scope starts before opening brace.
     scope()->set_start_position(scanner()->location().beg_pos);
     typename Types::Target target(this, body);
 
@@ -5109,10 +5108,9 @@ typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseBlock(
     }
 
     Expect(Token::RBRACE, CHECK_OK_CUSTOM(NullStatement));
-    // Scope ends after closing brace.
-    scope()->set_end_position(scanner()->location().end_pos);
-    // Coverage range uses position before closing brace.
-    impl()->RecordBlockSourceRange(body, scanner()->location().beg_pos);
+    int end_pos = end_position();
+    scope()->set_end_position(end_pos);
+    impl()->RecordBlockSourceRange(body, end_pos);
     body->set_scope(scope()->FinalizeBlockScope());
   }
   return body;

test/mjsunit/code-coverage-block.js

@@ -471,7 +471,7 @@ TestCoverage(
  {"start":472,"end":503,"count":0},
  {"start":626,"end":653,"count":0},
  {"start":768,"end":803,"count":0},
- {"start":867,"end":868,"count":0}]
+ {"start":867,"end":869,"count":0}]
 );
 
 TestCoverage(
@@ -847,7 +847,7 @@ Util.escape("foo.bar");                   // 0400
 [{"start":0,"end":449,"count":1},
  {"start":64,"end":351,"count":1},
  {"start":112,"end":203,"count":0},
- {"start":268,"end":350,"count":0}]
+ {"start":303,"end":350,"count":0}]
 );
 
 %DebugToggleBlockCoverage(false);

test/mjsunit/regress/regress-8237.js

-// Copyright 2018 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --allow-natives-syntax --no-always-opt
-// Files: test/mjsunit/code-coverage-utils.js
-
-%DebugToggleBlockCoverage(true);
-
-TestCoverage(
-"Repro for the bug",
-`
-function lib (n) {                        // 0000
-  if (n >= 0) {                           // 0050
-    if (n < 0) {                          // 0100
-      return;                             // 0150
-    }                                     // 0200
-  } else if (foo()) {                     // 0250
-  }                                       // 0300
-}                                         // 0350
-function foo () {                         // 0400
-  console.log('foo')                      // 0450
-  return false                            // 0500
-}                                         // 0550
-lib(1)                                    // 0600
-`,
-[{"start":0,"end":649,"count":1},
-{"start":0,"end":351,"count":1},
-{"start":115,"end":205,"count":0},
-{"start":253,"end":303,"count":0},
-{"start":400,"end":551,"count":0}]
-);
-
-TestCoverage(
-"Variant with omitted brackets",
-`
-function lib (n) {                        // 0000
-  if (n >= 0) {                           // 0050
-    if (n < 0)                            // 0100
-      return;                             // 0150
-  }                                       // 0200
-  else if (foo());                        // 0250
-}                                         // 0300
-function foo () {                         // 0350
-  console.log('foo')                      // 0400
-  return false                            // 0450
-}                                         // 0500
-lib(1)                                    // 0550
-`,
-[{"start":0,"end":599,"count":1},
-{"start":0,"end":301,"count":1},
-{"start":156,"end":163,"count":0},
-{"start":203,"end":268,"count":0},
-{"start":350,"end":501,"count":0}]
-);
-
-%DebugToggleBlockCoverage(false);