Move windows С++ mangle to frontend
different changes
Merge pull request #3160 from IgorStepanov/cppmanglewindows

Move C++ mangle to frontend in windows
fix Issue 12045 - Destructor call omitted for NRVO'd struct in exceptional case
Use Visitor for correct AST rewriting and CTFE interpretation
[Refactoring] Do return exp tweaking also in NrvoWalker
fix Issue 10929 - [CTFE] Destructor errornously gets called on NRVO-ed structs?