Many quoted code blocks were not in sync with the actual toy.cpp
files. Improve tutorial text slightly in several places.
Added some step descriptions crucial to avoid crashes (like
InitializeNativeTarget* calls).
Solve/workaround problems with Windows (JIT'ed method not found, using
custom and standard library functions from host process).
Patch by: Moritz Kroll <moritz.kroll@gmx.de>
Differential Revision: https://reviews.llvm.org/D29864
llvm-svn: 294870