Fix TypedArray/ArrayBuffer post-merge

[zpao]

It seems like a few things changed in the past 6 months and we either need to just make some tweaks here or rethink how we're doing typed array / array buffer stuff. We should probably also look at a newer v8 to see how things have changed on that side too.

I poked at some of these errors and some are easy (for example, isObjectProxy just becomes isProxy, JSProxy is gone in favor of just Proxy)

/Users/pao/Code/v8monkey/js/src/v8api/object.cpp: In function ‘JSObject* v8::grabTypedArray(JSObject*)’:
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:581: error: ‘struct JSObject’ has no member named ‘isObjectProxy’
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:583: error: cannot convert ‘JSString*’ to ‘JSContext*’ for argument ‘1’ to ‘jsid INTERNED_STRING_TO_JSID(JSContext*, JSString*)’
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:585: error: ‘js::JSProxy’ has not been declared
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp: In member function ‘void v8::Object::SetIndexedPropertiesToExternalArrayData(void*, v8::ExternalArrayType, int)’:
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:600: error: ‘fromJSObject’ is not a member of ‘js::TypedArray’
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:602: error: no matching function for call to ‘js::TypedArray::slotWidth()’
../js/src/jstypedarray.h:251: note: candidates are: static uint32 js::TypedArray::slotWidth(int)
../js/src/jstypedarray.h:272: note:                 static int js::TypedArray::slotWidth(JSObject*)
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:604: error: ‘struct js::TypedArray’ has no member named ‘buffer’
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:605: error: ‘struct js::ArrayBuffer’ has no member named ‘freeStorage’
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp: In member function ‘void* v8::Object::GetIndexedPropertiesExternalArrayData()’:
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:621: error: ‘fromJSObject’ is not a member of ‘js::TypedArray’
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:623: error: ‘struct js::TypedArray’ has no member named ‘data’
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp: In member function ‘int v8::Object::GetIndexedPropertiesExternalArrayDataLength()’:
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:638: error: ‘fromJSObject’ is not a member of ‘js::TypedArray’
/Users/pao/Code/v8monkey/js/src/v8api/object.cpp:639: error: ‘struct js::TypedArray’ has no member named ‘byteLength’
functiontemplate.cpp