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

src/debug/debug.cc

Index: src/debug/debug.cc
diff --git a/src/debug/debug.cc b/src/debug/debug.cc
index a21bfde25c1c5fab931337dc0679f97ddf16e9a9..038a054b7fc9d1630d4c8e074787b76ada5723f0 100644
--- a/src/debug/debug.cc
+++ b/src/debug/debug.cc
@@ -193,7 +193,6 @@ int CodeBreakIterator::GetModeMask(BreakLocatorType type) {
   }
   if (type == ALL_BREAK_LOCATIONS) {
     mask |= RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT_AT_POSITION);
-    mask |= RelocInfo::ModeMask(RelocInfo::DEBUGGER_STATEMENT);
   }
   return mask;
 }
@@ -219,8 +218,7 @@ void CodeBreakIterator::Next() {
     source_position_iterator_.Advance();
   }
 
-  DCHECK(RelocInfo::IsDebugBreakSlot(rmode()) ||
-         RelocInfo::IsDebuggerStatement(rmode()));
+  DCHECK(RelocInfo::IsDebugBreakSlot(rmode()));
   break_index_++;
 }
 
@@ -233,8 +231,6 @@ DebugBreakType CodeBreakIterator::GetDebugBreakType() {
     return isolate()->is_tail_call_elimination_enabled()
                ? DEBUG_BREAK_SLOT_AT_TAIL_CALL
                : DEBUG_BREAK_SLOT_AT_CALL;
-  } else if (RelocInfo::IsDebuggerStatement(rmode())) {
-    return DEBUGGER_STATEMENT;
   } else if (RelocInfo::IsDebugBreakSlot(rmode())) {
     return DEBUG_BREAK_SLOT;
   } else {
@@ -250,7 +246,6 @@ void CodeBreakIterator::SkipToPosition(int position,
 
 void CodeBreakIterator::SetDebugBreak() {
   DebugBreakType debug_break_type = GetDebugBreakType();
-  if (debug_break_type == DEBUGGER_STATEMENT) return;
   DCHECK(debug_break_type >= DEBUG_BREAK_SLOT);
   Builtins* builtins = isolate()->builtins();
   Handle<Code> target = debug_break_type == DEBUG_BREAK_SLOT_AT_RETURN
@@ -261,14 +256,12 @@ void CodeBreakIterator::SetDebugBreak() {
 
 void CodeBreakIterator::ClearDebugBreak() {
   DebugBreakType debug_break_type = GetDebugBreakType();
-  if (debug_break_type == DEBUGGER_STATEMENT) return;
   DCHECK(debug_break_type >= DEBUG_BREAK_SLOT);
   DebugCodegen::ClearDebugBreakSlot(isolate(), rinfo()->pc());
 }
 
 bool CodeBreakIterator::IsDebugBreak() {
   DebugBreakType debug_break_type = GetDebugBreakType();
-  if (debug_break_type == DEBUGGER_STATEMENT) return false;
   DCHECK(debug_break_type >= DEBUG_BREAK_SLOT);
   return DebugCodegen::DebugBreakSlotIsPatched(rinfo()->pc());
 }