Avoid pre-aging when debugger is active

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 52d8a4c3579f68f3bed2501ac4d5ac1bb9468006..6e3557797a99b021fc54d234b8831bba0fcc3820 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -35,6 +35,7 @@
 #include "codegen.h"
 #include "cpu-profiler.h"
 #include "debug.h"
+#include "isolate-inl.h"
 #include "runtime.h"
 
 namespace v8 {
@@ -4596,7 +4597,8 @@ void MacroAssembler::Prologue(PrologueFrameMode frame_mode) {
       this, kNoCodeAgeSequenceLength * Assembler::kInstrSize);
     // The following three instructions must remain together and unmodified
     // for code aging to work properly.
-    if (FLAG_optimize_for_size && FLAG_age_code) {
+    if (FLAG_optimize_for_size && FLAG_age_code &&
+        !isolate()->IsDebuggerActive()) {
       // Pre-age the code.
       Code* stub = Code::GetPreAgedCodeAgeStub(isolate());
       nop(Assembler::CODE_AGE_MARKER_NOP);