Fix printing of multiline constants

Signed-off-by: Alexandre Terrasa <alexandre.terrasa@shopify.com>

Author: Morriar

lib/rbi/printer.rb

@@ -675,6 +675,13 @@ def oneline?(node)
         node.comments.empty? && node.empty?
       when Attr
         node.comments.empty? && node.sigs.empty?
+      when Const
+        return false unless node.comments.empty?
+
+        loc = node.loc
+        return true unless loc
+
+        loc.begin_line == loc.end_line
       when Method
         node.comments.empty? && node.sigs.empty? && node.params.all? { |p| p.comments.empty? }
       when Sig

test/rbi/printer_test.rb

@@ -1113,8 +1113,10 @@ class << self; end
         class TE < T::Enum; end
         # file.rbi:1:3-2:4
         class TS < T::Struct; end
+
         # file.rbi:1:3-2:4
         C = 42
+
         # file.rbi:1:3-2:4
         extend E
         # file.rbi:1:3-2:4