Use a different map to distinguish eval contexts

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index 7362a3857229301fdb21a27e827cb14190c391bd..82a53a724ae4afc43653ccd87f5145447f576e6c 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -296,8 +296,9 @@ class V8_EXPORT_PRIVATE Factory final {
                                    Handle<JSFunction> function,
                                    Handle<ScopeInfo> scope_info);
 
-  // Create a function context.
-  Handle<Context> NewFunctionContext(int length, Handle<JSFunction> function);
+  // Create a function or eval context.

[adamk, 2016/12/14 12:23:31]

Can you mention here that scope_type should be one of FUNCTION_SCOPE/EVAL_SCOPE?

[Dan Ehrenberg, 2016/12/14 22:53:30]

There are tons of places where scope_type is an instance variable or argument.
Should I put that everywhere? I thought it might be enough to have the DCHECKs.

[adamk, 2016/12/15 08:46:52]

I commented on this case just because it happened to have a comment already. I
don't think you need to sprinkle this comment everywhere.

Also note that UNREACHABLE() is a CHECK, not a DCHECK (I think that's OK, just
want to make sure you're aware).

+  Handle<Context> NewFunctionContext(int length, Handle<JSFunction> function,
+                                     ScopeType scope_type);
 
   // Create a catch context.
   Handle<Context> NewCatchContext(Handle<JSFunction> function,