This CL adds support for:
* conditional breaks in setBreakpoint,
* locals in frame.local{Count,Name,Value},
* evaluation on a frame in frame.evaluate,
* and more detailed scope information in scopeObject.

Uses of several functions that are not covered by the
inspector protocol and are only used in tests have been removed.

Local handling has been modified to also include arguments as locals.
Inspector differs in this regard from our FrameDetails in that
arguments are always shown as locals. Argument-related functions
were removed.

BUG=v8:5530

Review-Url: https://codereview.chromium.org/2491543002
Cr-Commit-Position: refs/heads/master@{#40917}

In the debugger we are interested in getting the context for the
current frame, which is usually a function context. To do that,
we used to call Context::declaration_context, which may also
return a block context. This is wrong and can lead to crashes.
Instead, we now use a newly introduced Context::closure_context,
which skips block contexts. This works fine for the debugger,
since we have other means to find and materialize block contexts.

R=rossberg@chromium.org
BUG=chromium:582051
LOG=N

Review URL: https://codereview.chromium.org/1648263002

Cr-Commit-Position: refs/heads/master@{#33627}