EE/JIT: Do not invoke parent's ctors/dtors from main()! (PR3897)

On Mingw and Cygwin, the symbol __main is resolved to
callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
(and register wrong callee's dtors with atexit(3)).
We expect, by callee, ExecutionEngine::runStaticConstructorsDestructors()
is called before ExecutionEngine::runFunctionAsMain() is called.

llvm-svn: 112474