retdec-llvmir2hll fails in SimpleCopyPropagationOptimizer due to insufficient stack space

Hello!

Decompiling (retdec-llvmir2hll) Teslacrypt (https://github.com/ytisf/theZoo/tree/master/malwares/Binaries/Ransomware.TeslaCrypt)
fails with a huge stacktrace for reasons I currently don't understand:

```
Running phase: alias analysis [simple] ( 8.13s )
Running phase: optimizations [normal] ( 8.41s )
-> running RemoveUselessCastsOptimizer ( 8.41s )
-> running UnusedGlobalVarOptimizer ( 8.65s )
-> running DeadLocalAssignOptimizer ( 8.91s )
-> running SimpleCopyPropagationOptimizer ( 12.34s )
#0 0x000000000096e4c5 llvm::sys::PrintStackTrace(llvm::raw_ostream&) (/usr/local/bin/retdec-llvmir2hll+0x96e4c5)
#1 0x000000000096c29e llvm::sys::RunSignalHandlers() (/usr/local/bin/retdec-llvmir2hll+0x96c29e)
#2 0x000000000096c4d6 SignalHandler(int) (/usr/local/bin/retdec-llvmir2hll+0x96c4d6)
#3 0x00007faa50423f70 __restore_rt (/lib64/libpthread.so.0+0x11f70)
#4 0x000000000050ba1a std::pair >, bool> std::_Rb_tree, std::shared_ptr, std::_Identity >, std::less >, std::allocator > >::_M_insert_unique const&>(std::shared_ptr const&) (/usr/local/bin/retdec-llvmir2hll+0x50ba1a)
#5 0x000000000053370a retdec::llvmir2hll::ValueAnalysis::visit(std::shared_ptr) (/usr/local/bin/retdec-llvmir2hll+0x53370a)
#6 0x000000000067d5fa retdec::llvmir2hll::Variable::accept(retdec::llvmir2hll::Visitor*) (/usr/local/bin/retdec-llvmir2hll+0x67d5fa)
#7 0x00000000008ab6e7 retdec::llvmir2hll::OrderedAllVisitor::visit(std::shared_ptr) (/usr/local/bin/retdec-llvmir2hll+0x8ab6e7)
#8 0x000000000053004e retdec::llvmir2hll::ValueAnalysis::visit(std::shared_ptr) (/usr/local/bin/retdec-llvmir2hll+0x53004e)
#9 0x00000000005cafea retdec::llvmir2hll::AddOpExpr::accept(retdec::llvmir2hll::Visitor*) (/usr/local/bin/retdec-llvmir2hll+0x5cafea)
#10 0x000000000052e80f retdec::llvmir2hll::ValueAnalysis::visit(std::shared_ptr) (/usr/local/bin/retdec-llvmir2hll+0x52e80f)
#11 0x00000000005d2087 retdec::llvmir2hll::AssignStmt::accept(retdec::llvmir2hll::Visitor*) (/usr/local/bin/retdec-llvmir2hll+0x5d2087)
#12 0x000000000052e659 retdec::llvmir2hll::ValueAnalysis::getValueData(std::shared_ptr) (/usr/local/bin/retdec-llvmir2hll+0x52e659)
#13 0x000000000058e9a3 retdec::llvmir2hll::OptimFuncInfoCFGTraversal::updateFuncInfo(std::shared_ptr) (/usr/local/bin/retdec-llvmir2hll+0x58e9a3)
#14 0x000000000058f1e2 retdec::llvmir2hll::OptimFuncInfoCFGTraversal::visitStmt(std::shared_ptr) (/usr/local/bin/retdec-llvmir2hll+0x58f1e2)
#15 0x0000000000582308 retdec::llvmir2hll::CFGTraversal::performTraversalImpl(std::shared_ptr, __gnu_cxx::__normal_iterator const*, std::vector, std::allocator > > >) (/usr/local/bin/retdec-llvmir2hll+0x582308)

[...]

#255 0x0000000000582476 retdec::llvmir2hll::CFGTraversal::performTraversalImpl(std::shared_ptr, __gnu_cxx::__normal_iterator const*, std::vector, std::allocator > > >) (/usr/local/bin/retdec-llvmir2hll+0x582476)
Stack dump:
0. Program arguments: /usr/local/bin/retdec-llvmir2hll -target-hll=c -var-renamer=readable -var-name-gen=fruit -var-name-gen-prefix= -call-info-obtainer=optim -arithm-expr-evaluator=c -validate-module -llvmir2bir-converter=orig -o [DIR]/teslacrypt/3372c1edab46837f1e973164fa2d726c5c5e17bcb888828ccd7c4dfcc234a370.c [DIR]/teslacrypt/3372c1edab46837f1e973164fa2d726c5c5e17bcb888828ccd7c4dfcc234a370.c.backend.bc -enable-debug -emit-debug-comments -config-path=[DIR]/teslacrypt/3372c1edab46837f1e973164fa2d726c5c5e17bcb888828ccd7c4dfcc234a370.c.json -max-memory-half-ram
1. Running pass 'Decompiler' on module '[DIR]/teslacrypt/3372c1edab46837f1e973164fa2d726c5c5e17bcb888828ccd7c4dfcc234a370.c.backend.bc'.
Error: Decompilation of file [DIR]/teslacrypt/3372c1edab46837f1e973164fa2d726c5c5e17bcb888828ccd7c4dfcc234a370.c.backend.bc failed
```

Reproduce the failure with retdec-llvmir2hll on the Teslacrypt input using the command shown in the report, focusing on SimpleCopyPropagationOptimizer, ValueAnalysis, and CFGTraversal in the stack trace. Trace the insufficient-stack-space path and verify that the same input completes decompilation without the failure.

Written by the indexing model from the issue text.