JIT: Compute EH liveness on all blocks instead of RPO blocks (#104321)

Since we can have blocks whose control flow we do not model (like throw helpers) we need to consider all blocks when computing the `exceptVars` and `finallyVars` sets. Fix #104315

Author: jakobbotsch

src/coreclr/jit/liveness.cpp

@@ -1783,9 +1783,8 @@ void Compiler::fgInterBlockLocalVarLiveness()
  VARSET_TP exceptVars(VarSetOps::MakeEmpty(this)); // vars live on entry to a handler
  VARSET_TP finallyVars(VarSetOps::MakeEmpty(this)); // vars live on exit of a 'finally' block
 
- for (unsigned i = m_dfsTree->GetPostOrderCount(); i != 0; i--)
+ for (BasicBlock* block : Blocks())
  {
- BasicBlock* block = m_dfsTree->GetPostOrder(i - 1);
  if (block->hasEHBoundaryIn())
  {
  // Note the set of variables live on entry to exception handler.