Validate self-type on Proc

Author: ksss

lib/rbs/types.rb

@@ -1427,6 +1427,7 @@ def to_s(level = 0)
       def each_type(&block)
         if block
           type.each_type(&block)
+          yield self_type if self_type
           self.block&.type&.each_type(&block)
           if self_type = self.block&.self_type
             yield self_type
@@ -1467,7 +1468,7 @@ def has_classish_type?
       end
 
       def with_nonreturn_void?
-        if type.with_nonreturn_void?
+        if type.with_nonreturn_void? || self_type&.with_nonreturn_void?
           true
         else
           if block = block()

test/rbs/types_test.rb

@@ -40,6 +40,7 @@ def test_has_self_type?
       "[self]",
       "Array[self]",
       "^(self) -> void",
+      "^() [self: self] -> void",
       "^() { () [self: self] -> void } -> void"
     ].each do |str|
       type = parse_type(str)
@@ -61,6 +62,7 @@ def test_has_classish_type?
       "class",
       "class?",
       "^() -> instance",
+      "^() [self: class] -> void",
       "^() { () [self: class] -> void } -> void"
     ].each do |str|
       type = parse_type(str)
@@ -80,7 +82,8 @@ def test_with_nonreturn_void?
     [
       "void",
       "[void]",
-      "void?"
+      "void?",
+      "^() [self: void] -> void"
     ].each do |str|
       type = parse_type(str)
       assert_predicate type, :with_nonreturn_void?