PPC: [interpreter] Add basic framework for bytecode handler code generation.

PPC: [interpreter] Add basic framework for bytecode handler code generation.

Port 7877c4e0c77b5c2b97678406eab7e9ad6eba4a4d

Original commit message:
    Adds basic support for generation of interpreter bytecode handler code
    snippets. The InterpreterAssembler class exposes a set of low level,
    interpreter specific operations which can be used to build a Turbofan
    graph. The Interpreter class generates a bytecode handler snippet for
    each bytecode by assembling operations using an InterpreterAssembler.

    Currently only two simple bytecodes are supported: LoadLiteral0 and Return.

R=rmcilroy@chromium.org, dstence@us.ibm.com, michael_dawson@ca.ibm.com
BUG=

Committed: https://crrev.com/3144d1f1014042c4f0351bb9bea6540a8f91a1c9
Cr-Commit-Position: refs/heads/master@{#29822}

[dstence, 2015-07-23 16:11:57]

lgtm

[MTBrandyberry, 2015-07-23 16:12:50]

The CQ bit was checked by mbrandy@us.ibm.com

[commit-bot: I haz the power, 2015-07-23 16:12:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1250723003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1250723003/1

[commit-bot: I haz the power, 2015-07-23 16:35:30]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-23 16:35:53]

Patchset 1 (id:??) landed as
https://crrev.com/3144d1f1014042c4f0351bb9bea6540a8f91a1c9
Cr-Commit-Position: refs/heads/master@{#29822}