fix incorrect cast
Merge pull request #425 from 9rnsr/fixRightThis

Fix right this check
add SectionGroup

- unify interface to platform specific section handling
- static executables have a single SectionGroup
- each shared library adds another SectionGroup
- use new DSO code for ModuleInfos
.minfo null pointers were fixed in dmd

- ELF D-Programming-Language/dmd/a1079c33960a85578fbac30c8afee7af7b0b8684