drsyms: honor mangling flags to query routines on Windows

_From [rnk@google.com](https://code.google.com/u/rnk@google.com/) on November 04, 2011 14:52:15_

We decided that always requesting mangled symbols by turning off SYMOPT_UNDNAME was too much of a performance loss to support, and had major complications with respect to public and private symbols (issue #558). Instead, we chose to ignore the mangling flags for simplicity and performance and just get the default demangled symbols on Windows. This issue covers adding support to honor the mangling flags so that users can get fully mangled names and fully demangled names (most importantly, ones with parameter types).

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=601_