merge revision(s) 62115: [Backport #14421]

	proc: fix super_method segfault after bind

	* proc.c: handle undefined iclass
	  [ruby-core:85231] [Bug #14421]

	From: Eric Wong <e@80x24.org>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@62507 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

proc.c

@@ -2720,6 +2720,7 @@ method_super_method(VALUE method)
 
     TypedData_Get_Struct(method, struct METHOD, &method_data_type, data);
     iclass = data->iclass;
+    if (!iclass) return Qnil;
     super_class = RCLASS_SUPER(RCLASS_ORIGIN(iclass));
     mid = data->me->called_id;
     if (!super_class) return Qnil;

test/ruby/test_method.rb

@@ -926,6 +926,11 @@ def test_super_method_with_prepended_module
     assert_equal(m1.source_location, m2.source_location, bug)
   end
 
+  def test_super_method_after_bind
+    assert_nil String.instance_method(:length).bind(String.new).super_method,
+      '[ruby-core:85231] [Bug #14421]'
+  end
+
   def rest_parameter(*rest)
     rest
   end

version.h

@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.5.0"
 #define RUBY_RELEASE_DATE "2018-02-21"
-#define RUBY_PATCHLEVEL 25
+#define RUBY_PATCHLEVEL 26
 
 #define RUBY_RELEASE_YEAR 2018
 #define RUBY_RELEASE_MONTH 2