DFG should be able to compile StringReplace

DFG should be able to compile StringReplace
https://bugs.webkit.org/show_bug.cgi?id=154979

Reviewed by Benjamin Poulain.

Source/JavaScriptCore:

Adds support for StringReplace to the DFG tier. This is a 3% speed-up on Octane/regexp.

* dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::handleIntrinsicCall):
* dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::speculateFinalObject):
(JSC::DFG::SpeculativeJIT::speculateRegExpObject):
(JSC::DFG::SpeculativeJIT::speculateObjectOrOther):
* dfg/DFGSpeculativeJIT.h:
(JSC::DFG::SpeculativeJIT::callOperation):
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* jit/JITOperations.h:

LayoutTests:

Add a microbenchmark for a case of StringReplace that we hadn't covered with a microbenchmark
yet: using something absurd for the replace value. This is interesting for implementing the
32_64 version of StringReplace, which gets really weird in the absurd case because of how it
consumes the entire register file while making the call on x86-32.

* js/regress/script-tests/string-replace-generic.js: Added.
* js/regress/string-replace-generic-expected.txt: Added.
* js/regress/string-replace-generic.html: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@197520 268f45cc-cd09-0410-ab3c-d52691b4dbfc