Fix Binding#caller_locations arity (JRuby warn uplevel)

Binding#caller and #caller_locations were defined with arity 0..1, but
Kernel#caller/#caller_locations accept (start, length). When warn(uplevel:)
dispatches to caller_locations on a Binding receiver — as it does under
JRuby's pure-Ruby warn — it passes 2 args and raised ArgumentError. Widen
both to accept the optional length, keeping the 0/1-arg behavior unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: trans

HISTORY.md

@@ -14,6 +14,10 @@ Changes:
   * Restore `Range#overlap?` for Ruby < 3.3. It was dropped in 3.2.0 (since Ruby
     3.3 added a native one), which left 3.1/3.2 users without it. It is now
     defined only when missing, so it never replaces the built-in on 3.3+.
+  * Widen `Binding#caller` and `Binding#caller_locations` to accept the optional
+    `length` argument (matching `Kernel#caller`/`#caller_locations`). The
+    too-narrow arity raised `ArgumentError` when `warn(uplevel:)` dispatched to
+    them under JRuby's pure-Ruby `warn`.
 
 * Internal
 

lib/core/facets/binding/caller.rb

@@ -4,14 +4,18 @@ class Binding
 
   # Returns the call stack, same format as Kernel#caller()
   #
-  def caller( skip=0 )
-    eval("caller(#{skip})")
+  # Accepts the same `(start, length)` arguments as Kernel#caller.
+  #
+  def caller( start=0, length=nil )
+    length ? eval("caller(#{start}, #{length})") : eval("caller(#{start})")
   end
 
   # Returns the call stack, same format as Kernel#caller_locations()
   #
-  def caller_locations( skip=0 )
-    eval("caller_locations(#{skip})")
+  # Accepts the same `(start, length)` arguments as Kernel#caller_locations.
+  #
+  def caller_locations( start=0, length=nil )
+    length ? eval("caller_locations(#{start}, #{length})") : eval("caller_locations(#{start})")
   end
 
   # Return the line number on which the binding was created.