IfNode::fold_compares() requires ctrl has single output. I found a fold-compares case is postpone until IterGVN2.  The reason is that a dead region prevents IfNode::fold_compares() from transforming code. 


here is an example.  At beginning of IterGVN,  the control of 205 If is 194 Region. 
```
 205  If  ===  194  204  [[ 206  207 ]] P=1.000000, C=6784.000000  Type:{0:control, 1:control} !jvms: java.time.temporal.ChronoField::isDateBased @ bci:23 (line 687) java.time.chrono.ChronoLocalDate::isSupported @ bci:8 (line 388)
 194  Region  === _  150  [[ 205 ]]   Type:control !jvms: java.time.temporal.ChronoField::isDateBased @ bci:20 (line 687) java.time.chrono.ChronoLocalDate::isSupported @ bci:8 (line 388)
```

IfNode::Ideal() calls Node::remove_dead_region() for 205. it simplified code a little bit. IfNode's control changes from 194 to 150. 

```
 150  IfFalse  ===  148  [[ 194  205 ]] #0  Type:control !jvms: java.time.temporal.ChronoField::isDateBased @ bci:10 (line 687) java.time.chrono.ChronoLocalDate::isSupported @ bci:8 (line 388)
 205  If  ===  150  204  [[ 206  207 ]] P=1.000000, C=6784.000000  Type:{0:control, 1:control} !jvms: java.time.temporal.ChronoField::isDateBased @ bci:23 (line 687) java.time.chrono.ChronoLocalDate::isSupported @ bci:8 (line 388)
 194  Region  === _  150  [[]]   Type:control !jvms: java.time.temporal.ChronoField::isDateBased @ bci:20 (line 687) java.time.chrono.ChronoLocalDate::isSupported @ bci:8 (line 388)
```

Even 194 Region is dead, but igvn can't remove it in time. This code shape still miss IfNode::fold_compares() because 150's output isn't single.

    if (is_ctrl_folds(ctrl, igvn) && ctrl->outcnt() == 1) {}