Use a different map to distinguish eval contexts

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index c77902f0f634f4a8055df8f9c6b254fd63ad5ac6..599e43ef13e110eadf701120ce13b0466d178998 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -77,6 +77,7 @@ using v8::MemoryPressureLevel;
   /* Context maps */                                                           \
   V(Map, native_context_map, NativeContextMap)                                 \
   V(Map, module_context_map, ModuleContextMap)                                 \
+  V(Map, eval_context_map, EvalContextMap)                                     \
   V(Map, script_context_map, ScriptContextMap)                                 \
   V(Map, block_context_map, BlockContextMap)                                   \
   V(Map, catch_context_map, CatchContextMap)                                   \
@@ -295,6 +296,7 @@ using v8::MemoryPressureLevel;
   V(WithContextMap)                     \
   V(BlockContextMap)                    \
   V(ModuleContextMap)                   \
+  V(EvalContextMap)                     \
   V(ScriptContextMap)                   \
   V(UndefinedMap)                       \
   V(TheHoleMap)                         \