MIPS: port Implement set trap for proxies, and revamp class hierarchy in preparation

MIPS: port Implement set trap for proxies, and revamp class hierarchy in preparation

Ported commits: r8126 (6461bae)

Original commit message:
- Introduce a class JSReceiver, that is a common superclass of JSObject and
JSProxy. Use JSReceiver where appropriate (probably lots of places that we
still have to migrate, but we will find those later with proxy test suite).
- Move appropriate methods to JSReceiver class (SetProperty,
GetPropertyAttribute, Get/SetPrototype, Lookup, and so on).
- Introduce new JSFunctionProxy subclass of JSProxy. Currently only a stub.
- Overhaul enum InstanceType:
* Introduce FIRST/LAST_SPEC_OBJECT_TYPE that ranges over all types that
represent JS objects, and use that consistently to check language types.
* Rename FIRST/LAST_JS_OBJECT_TYPE and FIRST/LAST_FUNCTION_CLASS_TYPE
to FIRST/LAST_[NON]CALLABLE_SPEC_OBJECT_TYPE for clarity.
* Eliminate the overlap over JS_REGEXP_TYPE.
* Also replace FIRST_JS_OBJECT with FIRST_JS_RECEIVER, but only use it where
we exclusively talk about the internal representation type.
* Insert JS_PROXY and JS_FUNCTION_PROXY in the appropriate places.
- Fix all checks concerning classification, especially for functions, to
use the CALLABLE_SPEC_OBJECT range (that includes funciton proxies).
- Handle proxies in SetProperty (that was the easiest part :) ).
- A few simple test cases.

BUG=
TEST=

Committed: http://code.google.com/p/v8/source/detail?r=8175

[Mads Ager (chromium), 2011-06-06 08:44:20]

LGTM. I will address nit and land.

http://codereview.chromium.org/7024041/diff/1/src/mips/full-codegen-mips.cc
File src/mips/full-codegen-mips.cc (right):

http://codereview.chromium.org/7024041/diff/1/src/mips/full-codegen-mips.cc#n...
src/mips/full-codegen-mips.cc:2482: Split(le, a1,
Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE), if_true, if_false, fall_through);
Line too long.