[turbofan] Remove obsolete JSDebugger operator.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index a64e5a9c6e3df0af9fe750adce54838dfa0d60ed..85b0c3e14029d6ce93a88970fbb3226a02db0cfb 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -1554,12 +1554,6 @@ Bounds Typer::Visitor::TypeJSCallRuntime(Node* node) {
 }
 
 
-Bounds Typer::Visitor::TypeJSDebugger(Node* node) {
-  UNREACHABLE();
-  return Bounds();
-}
-
-
 Bounds Typer::Visitor::TypeJSStackCheck(Node* node) {
   return Bounds::Unbounded(zone());
 }