https://bugs.webkit.org/show_bug.cgi?id=127127.

Reviewed by Geoffrey Garen.

In order to implement bytecode level breakpoints, we need a mechanism
for computing the best fit op_debug bytecode offset for any valid given
line and column value in the source. The "best fit" op_debug bytecode
in this case is defined below in the comment for
UnlinkedCodeBlock::opDebugBytecodeOffsetForLineAndColumn().

* GNUmakefile.list.am:
* JavaScriptCore.vcxproj/JavaScriptCore.vcxproj:
* JavaScriptCore.vcxproj/JavaScriptCore.vcxproj.filters:
* JavaScriptCore.xcodeproj/project.pbxproj:
* bytecode/CodeBlock.cpp:
(JSC::CodeBlock::opDebugBytecodeOffsetForLineAndColumn):
- Convert the line and column to unlinked line and column values and
  pass them to UnlinkedCodeBlock::opDebugBytecodeOffsetForLineAndColumn()
  to do the real work.

* bytecode/CodeBlock.h:
* bytecode/LineColumnInfo.h: Added.
(JSC::LineColumnInfo::operator <):
(JSC::LineColumnInfo::LineColumnPair::LineColumnPair):
(JSC::LineColumnInfo::operator ==):
(JSC::LineColumnInfo::operator !=):
(JSC::LineColumnInfo::operator <=):
(JSC::LineColumnInfo::operator >):
(JSC::LineColumnInfo::operator >=):
* bytecode/LineInfo.h: Removed.

* bytecode/UnlinkedCodeBlock.cpp:
(JSC::UnlinkedCodeBlock::decodeExpressionRangeLineAndColumn):
- Factored this out of expressionRangeForBytecodeOffset() so that it can
  be called from multiple places.
(JSC::dumpLineColumnEntry):
(JSC::UnlinkedCodeBlock::dumpExpressionRangeInfo):
(JSC::UnlinkedCodeBlock::dumpOpDebugLineColumnInfoList):
- Some dumpers for debugging use only.
(JSC::UnlinkedCodeBlock::expressionRangeForBytecodeOffset):
(JSC::UnlinkedCodeBlock::opDebugBytecodeOffsetForLineAndColumn):
- Finds the earliest op_debug bytecode whose line and column matches the
  specified line and column values. If an exact match is not found, then
  finds the nearest op_debug bytecode that precedes the specified line
  and column values. If there are more than one op_debug at that preceding
  line and column value, then the earliest of those op_debug bytecodes will
  be be selected. The offset of the selected bytecode will be returned.

  We want the earliest one because when we have multiple op_debug bytecodes
  that map to a given line and column, a debugger user would expect to break
  on the first one and step through the rest thereafter if needed.

(JSC::compareLineColumnInfo):
(JSC::UnlinkedCodeBlock::opDebugLineColumnInfoList):
- Creates the sorted opDebugLineColumnInfoList on demand. This list is
  stored in the UnlinkedCodeBlock's rareData.
* bytecode/UnlinkedCodeBlock.h:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@162256 268f45cc-cd09-0410-ab3c-d52691b4dbfc