Use CompilerDirectives.shouldNotReachHere instead of IllegalStateException

Author: andrykonchin

src/main/java/org/truffleruby/parser/YARPLoadArgumentsTranslator.java

@@ -158,7 +158,7 @@ public RubyNode visitMultiTargetNode(Nodes.MultiTargetNode node) {
             readNode = new ReadPostArgumentNode(-index, getRequiredCount(), getOptionalCount(), hasRest(),
                     hasKeywordArguments());
         } else {
-            throw new IllegalStateException();
+            throw CompilerDirectives.shouldNotReachHere();
         }
 
         final var translator = new YARPMultiTargetNodeTranslator(node, language, yarpTranslator, readNode);
@@ -191,7 +191,7 @@ public RubyNode visitRequiredParameterNode(Nodes.RequiredParameterNode node) {
             readNode = new ReadPostArgumentNode(-index, getRequiredCount(), getOptionalCount(), hasRest(),
                     hasKeywordArguments());
         } else {
-            throw new IllegalStateException();
+            throw CompilerDirectives.shouldNotReachHere();
         }
 
         final int slot;

src/main/java/org/truffleruby/parser/YARPParametersNodeToDestructureTranslator.java

@@ -134,7 +134,7 @@ public RubyNode visitMultiTargetNode(Nodes.MultiTargetNode node) {
             readNode = new ReadBlockPostArgumentFromArrayNode(readArrayNode, -index, getRequiredCount(),
                     getOptionalCount(), hasRest());
         } else {
-            throw new IllegalStateException();
+            throw CompilerDirectives.shouldNotReachHere();
         }
 
         final var translator = new YARPMultiTargetNodeTranslator(node, language, yarpTranslator, readNode);
@@ -161,7 +161,7 @@ public RubyNode visitRequiredParameterNode(Nodes.RequiredParameterNode node) {
             readNode = new ReadBlockPostArgumentFromArrayNode(readArrayNode, -index, getRequiredCount(),
                     getOptionalCount(), hasRest());
         } else {
-            throw new IllegalStateException();
+            throw CompilerDirectives.shouldNotReachHere();
         }
 
         final int slot = environment.findFrameSlot(node.name);