[static analyzer] Fix DEREF_OF_NULL.DYN_CAST on loco/IR/CanonicalNodes.lst

[chunseoklee]

The whole lines on are reported as DEREF_OF_NULL.DYN_CAST in static analyzer.

For example,

ONE/compiler/loco/include/loco/IR/CanonicalNodes.lst

Line 37 in f9d691b

CANONICAL_NODE(ReLU6, ReLU6)

warning : Pointer '((struct Tanh*)return value of __dynamic_cast(...))', returned from function 'dynamic_cast' at CanonicalNodes.lst 38, may be NULL and is passed as 1st parameter in call to function '(anonymous namespace) CanonicalNodeDescBuilder visit' at CanonicalNodes.lst 38, where it is dereferenced at CanonicalNodeSummaryBuilder.cpp 244.

Let's fix it or ignore it.

[seanshpark]

I think it's related with adding a null check in
compiler/locop/src/CanonicalNodeSummaryBuilder.cpp

std::string opname(const loco::Node *node)
{
  if (node->dialect() == loco::CanonicalDialect::get())
  {

to

std::string opname(const loco::Node *node)
{
  if (node != nullptr && node->dialect() == loco::CanonicalDialect::get())
  {

[seanshpark]

Return value of a function 'loco::NamedEntity::name[abi:cxx11]' is dereferenced at PartitionPModules.cpp:98 without checking for NULL

I'll post a PR for this issue too

[seanshpark]

Same error but at CanonicalTypeForwardAlgorithm::visit'

[chunseoklee]

Since I do not have any good idea to resolve this in one shot, let's keep it as 'intentional'(ignored in system)