Debugger: make debug code on-stack replacement more robust.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index f5349038dac0335c088da76771c2ffd20ef22aec..7109d403f7653ff3f3d3a8c96f700db7dd1287c9 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -381,6 +381,9 @@ class RelocInfo {
     // Encoded internal reference, used only on MIPS, MIPS64 and PPC.
     INTERNAL_REFERENCE_ENCODED,
 
+    // Continuation points for a generator yield.
+    GENERATOR_CONTINUATION,
+
     // Marks constant and veneer pools. Only used on ARM and ARM64.
     // They use a custom noncompact encoding.
     CONST_POOL,
@@ -474,6 +477,9 @@ class RelocInfo {
   static inline bool IsCodeAgeSequence(Mode mode) {
     return mode == CODE_AGE_SEQUENCE;
   }
+  static inline bool IsGeneratorContinuation(Mode mode) {
+    return mode == GENERATOR_CONTINUATION;
+  }
   static inline int ModeMask(Mode mode) { return 1 << mode; }
 
   // Accessors