Clients are responsible for initializing the targets, remove it from the disassembler API.

This will break users of the LLVMCreateDisasm API (not that I know of any). They have to call the 
LLVMInitializeAll* functions from llvm-c/Target.h themselves now. edis' C API in all its horribleness 
should be unaffected.

llvm-svn: 144385