https://bugs.webkit.org/show_bug.cgi?id=91135

Reviewed by Geoffrey Garen.

Source/JavaScriptCore: 

This adds a Watchpoint subclass that will clear a structure stub (i.e.
a property access stub) when fired. The DFG stub generation code now
uses this optimization.

* CMakeLists.txt:
* GNUmakefile.list.am:
* JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCore.vcproj:
* JavaScriptCore.xcodeproj/project.pbxproj:
* Target.pri:
* bytecode/CodeBlock.cpp:
(JSC):
(JSC::CodeBlock::finalizeUnconditionally):
(JSC::CodeBlock::resetStub):
(JSC::CodeBlock::resetStubInternal):
* bytecode/CodeBlock.h:
(JSC):
(CodeBlock):
* bytecode/StructureStubClearingWatchpoint.cpp: Added.
(JSC):
(JSC::StructureStubClearingWatchpoint::~StructureStubClearingWatchpoint):
(JSC::StructureStubClearingWatchpoint::push):
(JSC::StructureStubClearingWatchpoint::fireInternal):
(JSC::WatchpointsOnStructureStubInfo::~WatchpointsOnStructureStubInfo):
(JSC::WatchpointsOnStructureStubInfo::addWatchpoint):
(JSC::WatchpointsOnStructureStubInfo::ensureReferenceAndAddWatchpoint):
* bytecode/StructureStubClearingWatchpoint.h: Added.
(JSC):
(StructureStubClearingWatchpoint):
(JSC::StructureStubClearingWatchpoint::StructureStubClearingWatchpoint):
(WatchpointsOnStructureStubInfo):
(JSC::WatchpointsOnStructureStubInfo::WatchpointsOnStructureStubInfo):
(JSC::WatchpointsOnStructureStubInfo::codeBlock):
(JSC::WatchpointsOnStructureStubInfo::stubInfo):
* bytecode/StructureStubInfo.h:
(JSC::StructureStubInfo::reset):
(JSC::StructureStubInfo::addWatchpoint):
(StructureStubInfo):
* dfg/DFGRepatch.cpp:
(JSC::DFG::addStructureTransitionCheck):
(DFG):
(JSC::DFG::generateProtoChainAccessStub):
(JSC::DFG::emitPutTransitionStub):
* jit/JumpReplacementWatchpoint.h:

LayoutTests: 

* fast/js/dfg-proto-stub-watchpoint-fire-expected.txt: Added.
* fast/js/dfg-proto-stub-watchpoint-fire.html: Added.
* fast/js/script-tests/dfg-proto-stub-watchpoint-fire.js: Added.
(A):
(B):
(foo):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@122544 268f45cc-cd09-0410-ab3c-d52691b4dbfc