[V8] MIPS: Renamed "symbols" to "internalized strings" throughout the code base, in preparation of the introduction of ES6 'symbols' (aka private/unique names).

Port r13781 (59f39a06)

Original commit message:
The SymbolTable became the StringTable. I also made sure to adapt all comments. The only remaining use of the term "symbol" (other than unrelated uses in the parser and such) is now 'NewSymbol' in the API and the 'V8.KeyedLoadGenericSymbol' counter, changing which might break embedders.

The one functional change in this CL is that I removed the former 'empty_string' constant, since it is redundant given the 'empty_symbol' constant that we also had (and both were used inconsistently).

BUG=

Review URL: https://codereview.chromium.org/12374074

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13807 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Change-Id: I2e5c705c88e43da9eb229d95429bea7a2bf49a7a
Signed-off-by: Peter Varga <pvarga@inf.u-szeged.hu>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
[V8] MIPS: Allocation Info Tracking, continued.

Port r13790 (0a70a3af)

Original commit message:
Addresses missing cases for array literals.
Adds support for "new Array()" call sites. This isn't complete yet, I have to run with --noinline_new.

BUG=

Review URL: https://codereview.chromium.org/12507006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13836 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Change-Id: I61e3a4b0095176fc8ba0cd007f13db5c4898d8cf
Signed-off-by: Peter Varga <pvarga@inf.u-szeged.hu>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
[V8] MIPS: ES6 symbols: Implement Symbol intrinsic and basic functionality

Port r13786 (b5e7a82a)

Original commit message:
- Add --harmony-symbols flag.
- Add Symbol constructor; allow symbols as (unreplaced) return value from constructors.
- Introduce %CreateSymbol and %_IsSymbol natives and respective instructions.
- Extend 'typeof' code generation to handle symbols.
- Extend CompareIC with a UNIQUE_NAMES state that (uniformly) handles internalized strings and symbols.
- Property lookup delegates to SymbolDelegate object for symbols, which only carries the toString method.
- Extend Object.prototype.toString to recognise symbols.

Per the current draft spec, symbols are actually pseudo objects that are frozen with a null prototype and only one property (toString). For simplicity, we do not treat them as proper objects for now, although typeof will return "object". Only property access works as if they were (frozen) objects (via the internal delegate object).

(Baseline CL: https://codereview.chromium.org/12223071/)

BUG=

Review URL: https://codereview.chromium.org/12447009

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13871 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Change-Id: I5fc2d443b2609ed8832b9bbd0225daf6d882a608
Signed-off-by: Peter Varga <pvarga@inf.u-szeged.hu>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
[V8] MIPS: Fixed ASSERT in commit r13807.

BUG=

Review URL: https://codereview.chromium.org/12506006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13872 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Change-Id: I1f148a46978fe6469486223e4db9f554af796a98
Signed-off-by: Peter Varga <pvarga@inf.u-szeged.hu>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
[V8] MIPS: Polymorphism support for load IC.

Port r13801 (6de52924)

BUG=

Review URL: https://codereview.chromium.org/12560004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13873 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Change-Id: I14d70552755d08c539d5fbb3cb36ea64f4a5691a
Signed-off-by: Peter Varga <pvarga@inf.u-szeged.hu>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>