Add backed intrinsics to private functions exposed with private symbols in global...

Add backed intrinsics to private functions exposed with private symbols in global object
https://bugs.webkit.org/show_bug.cgi?id=144545

Reviewed by Darin Adler.

Math.abs and Math.floor have ASM intrinsics And it is further accelerated in DFG/FTL layers.
This patch adds intrinsic to private functions exposed with private symbols in global object,
@floor and @abs.

* runtime/JSGlobalObject.cpp:
(JSC::JSGlobalObject::init):
* runtime/JSGlobalObjectFunctions.cpp:
(JSC::globalPrivateFuncAbs): Deleted.
(JSC::globalPrivateFuncFloor): Deleted.
* runtime/MathObject.cpp:
* runtime/MathObject.h:
* tests/stress/array-from-abs-and-floor.js: Added.
(target1):
(target2):
(target3):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@183785 268f45cc-cd09-0410-ab3c-d52691b4dbfc