Avoid top-level search for nested constant reference from nil in defined?

Fixes [Bug #16332]

Constant access was changed to no longer allow top-level constant access
through `nil`, but `defined?` wasn't changed at the same time to stay
consistent.

Use a separate defined type to distinguish between a constant
referenced from the current lexical scope and one referenced from
another namespace.

1 files changed, 2 insertions, 1 deletions

diff --git a/iseq.h b/iseq.h
index c9cc12529b..1fcf7cb210 100644
--- a/iseq.h
+++ b/iseq.h
@@ -300,7 +300,8 @@ enum defined_type {
     DEFINED_EXPR,
     DEFINED_IVAR2,
     DEFINED_REF,
-    DEFINED_FUNC
+    DEFINED_FUNC,
+    DEFINED_CONST_FROM
 };
 
 VALUE rb_iseq_defined_string(enum defined_type type);