Minor code formatting fixes
Fix the test for potentially shared memory location

Mark ER rewriter introduced variable references, so they aren't
themselves instrumented.
Add ER rewriting in a few more places, where it is needed
Ensure the AST nodes have unique identifiers within a function

This is a requirement of the optimizing compiler. Assignment of the
unique ids is interleaved with parsing and id ranges for each function
are maintained via the FunctionState (cf. SetupFunctionState,
TearDownFunctionState).  When the ER rewriter needs to create new AST
nodes, it must ensure they do not conflict with existing ones. We
achieve this by recording the maximum id for each function literal and
then adjusting the id allocation via the AstNodeIdAllocationScope class.
Fix counting of function literal AST nodes

Count a function literal into the node count of the enclosing literal,
instead into its own node count.

ix counting of function literal node into the parent node count, not into its own
Do not process lazily parsed function by AstSlotCounter

If a function is not yet parsed (as indicated by its |body()| being
|NULL|), do not descend into it, as this will overwrite with zeros the
materialized literal count and other attributes already set by the
preparser.
Force eager compilation of the instrumentation function literals

If we do allow lazy compilation, the v8 will attempt to parse the
function literals, introduced by the ER instrumentation, but these
literals have no meaningful source locations and the parsing will
fail.
Remove redundant and possibly erroneous variable proxy creation

This is not needed due to the following commit:
  commit e9e35e9af2d47743f0437e6030a92be6de52e1b2
  Author: Momchil Velikov <momchil.velikov@gmail.com>
  Date:   Fri Aug 8 18:39:47 2014 +0300

    Avoid capture of local variables during instrumentation of Property nodes
Fix wrong instrumentation of the delete operator

The property is not actually read, but written. To be instrumented as a
write in the future.
Remove some unused code