Profiler directed clean-up of dex2oat.

Fix bad usage of std::string in: the verifier and compiler driver method
arguments, causing unnecessary boxing and allocations; in creating a symbol for
the dex compilation unit, that is only used in portable builds; in pattern
matching for intrinsics by name.

Make class linker dex and classes locks reader/writer to allow concurrent
dex cache or class querying. Refactor ComputeCompilingMethodsClass to pass in a
dex cache hint, to avoid taking any locks when the dex file of the compiling
method matches that of the field or method being resolved.

Make the RegType's HasClass method virtual to avoid frequent virtual method
dispatch. Make RegTypeCache GetFromId inlinable.

Various other bits of whitespace and formatting clean-up.

Change-Id: Id152e1e5a6fed2961dad0b612b7aa0c48001ef94