LDC - DMD sync strategy

[Trass3r via digitalmars-d-ldc]

with /d2Zi+ the stack trace is better:

llvm::ValueHandleBase::AddToExistingUseList(llvm::ValueHandleBase** 
List=0) Line 531
llvm::scc_iterator<llvm::CallGraph*,llvm::GraphTraits<llvm::CallGraph*> 
 >::DFSVisitChildren() Line 158
llvm::scc_iterator<llvm::CallGraph*,llvm::GraphTraits<llvm::CallGraph*> 
 >::GetNextSCC() Line 179
`anonymous namespace'::CGPassManager::runOnModule(llvm::Module & 
M=<struct at NULL>) Line 434
`anonymous namespace'::MPPassManager::runOnModule(llvm::Module & 
M={...}) Line 1625
llvm::legacy::PassManagerImpl::run(llvm::Module & M={...}) Line 
1734
ldc_optimize_module(llvm::Module* M=0x00000000024a6d20) Line 400

But it still makes no sense. In MPPassManager::runOnModule M 
looks fine and then in CGPassManager::runOnModule it's allegedly 
null.