Disable SharedArrayBuffers from Web API

Disable SharedArrayBuffers from Web API
https://bugs.webkit.org/show_bug.cgi?id=181266

Reviewed by Saam Barati.

JSTests:

Disabled SharedArrayBuffer tests.

* stress/SharedArrayBuffer-opt.js:
* stress/SharedArrayBuffer.js:
* stress/array-buffer-byte-length.js:
* stress/atomics-add-uint32.js:
* stress/atomics-known-int-use.js:
* stress/atomics-neg-zero.js:
* stress/atomics-store-return.js:
* stress/lars-sab-workers.js:
* stress/regress-159779-1.js:
* stress/regress-159779-2.js:
* stress/regress-170473.js:
* test262.yaml:

Source/JavaScriptCore:

Removed SharedArrayBuffer prototype and structure from GlobalObject creation
to disable.

* runtime/JSGlobalObject.cpp:
(JSC::JSGlobalObject::init):
(JSC::JSGlobalObject::visitChildren):
* runtime/JSGlobalObject.h:
(JSC::JSGlobalObject::arrayBufferPrototype const):
(JSC::JSGlobalObject::arrayBufferStructure const):

Source/WTF:

Turn off SharedArrayBuffers using a compile time flag ENABLE_SHARED_ARRAY_BUFFER.

* wtf/Platform.h:

LayoutTests:

Disabled SharedArrayBuffer tests.

* TestExpectations:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@226386 268f45cc-cd09-0410-ab3c-d52691b4dbfc