[debugger] remove debugger statement support from FCG/CS.

src/full-codegen/full-codegen.cc

Index: src/full-codegen/full-codegen.cc
diff --git a/src/full-codegen/full-codegen.cc b/src/full-codegen/full-codegen.cc
index 8063d4fae5e75f0c79b43908e499d112cf83ce9b..58872d08ab3487154c7ad05ad474da0957ad6520 100644
--- a/src/full-codegen/full-codegen.cc
+++ b/src/full-codegen/full-codegen.cc
@@ -1223,13 +1223,8 @@ void FullCodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
 
 
 void FullCodeGenerator::VisitDebuggerStatement(DebuggerStatement* stmt) {
-  Comment cmnt(masm_, "[ DebuggerStatement");
-  SetStatementPosition(stmt);
-
-  __ DebugBreak();
-  __ MaybeDropFrames();
-
-  PrepareForBailoutForId(stmt->DebugBreakId(), BailoutState::NO_REGISTERS);
+  // Debugger statement is not supported.
+  UNREACHABLE();
 }